Structural safety-based drum building parameterization design optimization method and system

Abstract

The invention discloses a drum building parameterization design optimization method and system based on structural safety, and relates to the technical field of building digital modeling. A Grasshopper parameterization platform is adopted, a parameterization geometric model with the adjustable size is obtained, and a finite element model is generated; setting analysis parameters on the parameterization platform, obtaining key performance indexes under the drum building load working condition through analysis based on a finite element model, and automatically positioning key components by adopting a component importance calculation method; carrying out size optimization on the key component according to a full stress criterion to obtain the minimum section size of the key component; and checking calculation of anti-overturning, stability and deflection of the optimized component is conducted through the load effect values in the bearing capacity limit state and the normal use limit state, if checking calculation results meet constraint conditions, checking calculation succeeds, and an optimization result is visually displayed. According to the method, parameterized design and structural optimization of the drum building are achieved, and structural safety and material economy are improved.

Description

Technical Field

[0001] The invention relates to the technical field of building digital modeling, and in particular to a parametric design optimization method and system for a drum tower based on structural safety. Background Art

[0002] In modern urban environments, the image of drum towers is widely used in high-speed rail stations, city squares, tourist attractions and other crowded areas, becoming an important driving force for the development of local culture and tourism. Guangxi Zhuang Autonomous Region, Guizhou Province, and Hunan Province, as places where the Dong people live, have preserved a large number of traditional wooden drum towers. With the rise of cultural tourism, the construction of new wooden drum towers is becoming increasingly frequent.

[0003] However, with the increasing number and scale of new drum tower projects and the increase in extreme weather and strong winds, new drum tower collapse accidents have occurred one after another, exposing the problem that the construction method based on practical experience is difficult to adapt to the growing demand for structural safety. In addition to causing economic damage, the occurrence of such accidents also further threatens the safety of people's lives and property.

[0004] Therefore, there is an urgent need for a parametric design optimization method that can improve the structural safety performance of the Drum Tower during the conceptual design stage and to develop a corresponding parametric design optimization platform. Summary of the invention

[0005] The purpose of the present invention is to provide a method and system for parametric design optimization of a drum tower based on structural safety, so as to realize parametric design and structural optimization of the drum tower and improve the safety of the drum tower structure and the economy of materials.

[0006] To achieve the above object, the present invention provides the following solutions:

[0007] A parametric design optimization method for a drum tower based on structural safety comprises the following steps:

[0008] S1. Construct a three-dimensional axis model of the Drum Tower, and import the three-dimensional axis model into the Rhino&Grasshopper parametric platform to obtain a parametric geometric model with adjustable size;

[0009] S2. Setting analysis parameters on the Rhino&Grasshopper parametric platform, wherein the analysis parameters include vertical load, wind load, material properties, section size, nodes and constraints, and obtaining key performance indicators of the Drum Tower under load conditions through finite element analysis on the Rhino&Grasshopper parametric platform based on a finite element model, wherein the key performance indicators include internal force, stress, deflection, material utilization, stability and strength;

[0010] S3. Based on the key performance indicators, a component importance calculation method is used to automatically locate key components in the structure of the Drum Tower, and a component importance distribution cloud map is generated to visualize the component importance;

[0011] S4. Optimizing the size of the key component according to the full stress criterion to obtain the minimum cross-sectional size of the optimized component under the ultimate load-bearing capacity state;

[0012] S5. Use the load effect values ​​under the ultimate bearing capacity state and the normal use limit state to verify the anti-overturning, stability and deflection of the optimized components. If the verification results meet the corresponding constraints, it means that the structural optimization of the Drum Tower is successful, and the optimization results are visualized.

[0013] Further, in S3, the component importance calculation method is used to evaluate the importance of each component based on the key performance indicators, including component unit redefinition, unit importance calculation and importance ranking visualization;

[0014] The component unit redefinition is the process of classifying and describing each component in the engineering structure, including redefining the material properties of the component and describing in detail the position, function and stress condition of the component in the drum tower structure;

[0015] Unit importance calculation is a key link in evaluating the importance of each component. It is used to develop a component importance evaluation method based on energy flow, comprehensively considering the basic properties of the component, the stress condition, and whether it meets engineering experience, and quantitatively calculate the importance of the component;

[0016] Importance ranking visualization is to display the calculated component importance index in an intuitive way, and to rank and label the importance of the components.

[0017] Furthermore, the step S4, optimizing the size of the key component according to the full stress criterion to obtain the minimum cross-sectional size of the optimized component under the ultimate strength bearing capacity state, specifically includes:

[0018] S401. Set a component size sequence arranged from small to large and input it into the Rhino&Grasshopper parametric platform as a design variable. Under the premise of satisfying the rationality of node connection and following the full stress design principle, use the optimized cross-section operator to perform iterative calculation to determine the minimum applicable cross-sectional size of the component.

[0019] S402. Check the safety index of the optimized and adjusted components and the overall structure. If the check result shows that the safety requirements are met, the current cross-sectional size is determined to be the optimal solution; otherwise, if it is not met, the range of the cross-sectional size must be readjusted.

[0020] Furthermore, in S401, an iterative calculation is performed using an optimized cross-section operator to determine the minimum applicable cross-sectional size of the component, specifically including:

[0021] S4011. Set the analysis conditions of the optimized cross-section operator: sort the cross-sectional dimensions of the components obtained in S401 to obtain a cross-sectional dimension list as a design variable; take the material utilization rate as the optimization target, obtain the component safety index according to the limit state design constraint conditions, and set the number of iterations;

[0022] S4012. In the optimized cross-section operator, under the premise of considering various mechanical effects, the cross-sectional dimensions of the components are taken as design variables, and minimizing the volume of materials used is taken as the objective function. A mathematical model for optimizing the dimensions of drum tower components is established to optimize the cross-section and obtain the optimal cross-sectional dimension set that minimizes the use of structural materials.

[0023] Furthermore, in S5, the anti-overturning calculation specifically includes the following steps:

[0024] S501. Perform overall structural overturning verification, the formula is:

[0025] M 抗(永久荷载+0.5活荷载) / M 倾(水平荷载设计值) ≥1.0 (3-4)

[0026] Assuming that the overturning moment calculation surface is the foundation bottom surface, and the force of the overturning moment calculation is the horizontal earthquake action or the standard value of the horizontal wind load, the overturning moment is:

[0027] M OV =V0(2H / 3+C) (3-5)

[0028] Where M OV ——Standard value of overturning moment; H——Height of the building above the ground, i.e., building height; C——Deepness of basement; V0——Standard value of total horizontal force;

[0029] Assuming the anti-overturning moment calculation point is the outer edge point of the foundation, and the anti-overturning moment calculation force is the representative value of the total gravity load, the anti-overturning moment is expressed as:

[0030] M R =GB / 2(3-6)

[0031] Where M R ——Standard value of anti-overturning moment; G——Representative value of total gravity load of upper part and basement foundation, i.e. standard value of permanent load + 0.5 standard value of live load; B——Width of bottom surface of basement.

[0032] Furthermore, in S5, the stability verification specifically includes the following steps:

[0033] S502. In Karamba3D, perform finite element calculation on the load effect value under the ultimate bearing capacity state of the structure, and calculate the stability coefficient φ of the axial compression member and the lateral stability coefficient φ of the bending member in Grasshopper. l and the reduction factor φ considering the combined effect of axial force and initial bending moment m , then φ, φ l ,φ m Substitute the stability constraint formula of the compression-bending member into Grasshopper to determine whether each type of member meets the stability constraint.

[0034] Use the following formula to determine whether the stability constraint is met:

[0035] The stability factor of axially compressed members is calculated according to the following formula:

[0036]

[0037] When λ>λ c hour:

[0038] When λ≤λ c hour:

[0039] Where, λ is the slenderness ratio of the compression member; i is the radius of gyration of the member section, in mm; l0 is the calculated length of the compression member, in mm; f ck ——The standard value of compressive strength of compression member materials is in N / mm 2 ; E k ——Standard value of elastic modulus of component material, in N / mm 2 ; a c 、b c 、c c ——Material correlation coefficient; β——Material shear deformation correlation coefficient;

[0040] The lateral stability factor of the bending member is calculated according to the following formula:

[0041]

[0042] When B >λ m hour:

[0043] When B ≤λ m hour:

[0044] Where: B ——The slenderness ratio of bending members should not be greater than 50; e ——calculated length of the bending member, in mm; b——section width of the bending member, in mm; h——section height of the bending member, in mm; f mk ——Standard value of bending strength of bending member material, in N / mm 2 ; a m 、b m 、c m ——Material correlation coefficient;

[0045] The reduction factor considering the combined effect of axial force and initial bending moment is calculated according to the following formula:

[0046]

[0047]

[0048] Where A is the calculated area of ​​the component cross section, in mm 2 .

[0049] Furthermore, the constraint conditions include the constraint conditions of the bending member and the compression bending member under the ultimate bearing capacity state and the constraint conditions under the normal use limit state respectively;

[0050] Under the ultimate bearing capacity state, the design requirements for the structural components of the Dong Drum Tower are as follows:

[0051] γ0S d ≤R d (3-7)

[0052] In the formula, γ0 is the structural importance coefficient; S d ——design value of effect of load combination; R d — design value of resistance of structural members;

[0053] The calculation requirements for the design value of the effect controlled by variable loads are as follows:

[0054]

[0055] In the formula, ——Partial coefficient of permanent load, which is 1.2 when the permanent load is unfavorable to the structure and less than 1.0 when it is favorable; ——The partial factor of variable load is 1.4; - Adjustment factor for variable loads taking into account the design service life; ——Load effect value calculated from the standard value of permanent load; ——Load effect value calculated from the standard value of variable load, where: It plays a controlling role in the variable load effects; ——Combination value coefficient of variable load; m, n——number of permanent and variable loads participating in the combination;

[0056] The restraint conditions for the flexural members are as follows:

[0057] Constraints under the ultimate bending capacity state:

[0058]

[0059] In the formula, f m ——Design value of flexural strength of component material, in N / mm 2 ; M——Design value of bending moment of bending member, in N·mm; W n ——Net section resistance moment of bending member, unit: mm 3 ;

[0060] Strength requirements under the ultimate shear bearing capacity state:

[0061]

[0062] Where:

[0063] f V ——Design values ​​of bending strength and shear strength along the grain of the component material; V——Design value of shear force of bending components; I——Full section moment of inertia of the component; b——Cross-sectional width of the component; S——Area moment of the cross-sectional area above the shear plane about the neutral axis;

[0064] Stability requirements under the ultimate bearing capacity state:

[0065]

[0066] in, ——lateral stability factor of bending members;

[0067] The constraints of compression-bending members are as follows:

[0068] Strength requirements under ultimate bearing capacity state:

[0069]

[0070] Where, N is the design value of axial pressure; M0 is the design value of the maximum initial bending moment at mid-span under lateral load; A n ——net cross-sectional area of ​​the component section; W n——Compute the full section resistance moment of the component; e0——The initial eccentricity of the axial pressure of the component, if uncertain, it shall be 0.05 times the section height of the component; f c 、f m ——Design values ​​of tensile strength and flexural strength along the grain of component materials after considering the adjustment coefficient;

[0071] Stability requirements under the ultimate bearing capacity state:

[0072]

[0073] In the formula, ——Stability coefficient of axially compressed members and reduction coefficient considering the combined effect of axial force and initial bending moment; A0——Calculated area of ​​the member cross section.

[0074] Furthermore, the key components include all wooden component units, beams, columns and rafters of the Drum Tower.

[0075] The present invention also provides a Drum Tower parametric design optimization system based on structural safety, which is used to execute the Drum Tower parametric design optimization method based on structural safety, comprising:

[0076] A construction module is used to construct a three-dimensional axis model of the Drum Tower, and import the three-dimensional axis model into the Rhino&Grasshopper parametric platform to obtain a parametric geometric model with adjustable size, define component units, and generate a finite element model;

[0077] A key performance indicator acquisition module is used to set analysis parameters on the Rhino&Grasshopper parametric platform, wherein the analysis parameters include vertical load, wind load, material properties, section size, nodes and constraint conditions, and based on a finite element model, obtain key performance indicators of the Drum Tower under load conditions through finite element analysis on the Rhino&Grasshopper parametric platform, wherein the key performance indicators include internal force, stress, deflection, material utilization, stability and strength;

[0078] A component importance calculation module is used to automatically locate key components in the structure of the Drum Tower based on the key performance indicators and using a component importance calculation method, and to generate a component importance distribution cloud map to visualize the component importance;

[0079] An optimization module is used to optimize the size of the key component according to the full stress criterion to obtain the minimum cross-sectional size of the optimized component under the ultimate load capacity state;

[0080] The result visualization module is used to verify the anti-overturning, stability and deflection of the optimized components using the load effect values ​​under the ultimate bearing capacity limit state and the normal use limit state. If the verification results meet the corresponding constraints, it indicates that the structural optimization of the Drum Tower is successful, and the optimization results are visualized.

[0081] According to the specific embodiments provided by the present invention, the present invention discloses the following technical effects: The present invention provides a parametric design optimization method and system for a drum tower based on structural safety. The method first establishes a mathematical model for optimizing the size of the Dong ethnic drum tower components: the cross-sectional size of the component is used as the design variable; the objective function is to minimize the volume of material used; based on the current national relevant standards such as the "Wood Structure Design Standard" and traditional construction logic, the optimization constraints are restricted - anti-overturning constraints, limit state constraints and size constraints. Secondly, an optimization strategy is formulated based on material utilization and component importance, and the full stress criterion is used as the structural optimization design algorithm. Finally, the optimal size of the component cross section is obtained through iterative calculation, and the constraints of structural anti-overturning and component strength, stability and deflection are verified.

[0082] In addition, the developed parametric platform integrates the three-dimensional model and component unit data of the drum tower, allowing designers to directly retrieve the required information, automatically generate a finite element analysis model, and perform structural safety analysis and target performance optimization. The present invention can provide technical support for the design of the drum tower and achieve a balance between safety and economy. The application of this platform not only improves the accuracy of the design scheme, but also provides a digital means for the inheritance and protection of the Dong nationality's architectural skills, ensuring that these valuable cultural heritages can be preserved and carried forward. BRIEF DESCRIPTION OF THE DRAWINGS

[0083] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0084] Figure 1 A schematic diagram of a parameterized structural optimization framework according to an embodiment of the present invention;

[0085] Figure 2 It is a schematic diagram of a finite element analysis framework of an embodiment of the present invention;

[0086] Figure 3 This is a schematic diagram of a component importance evaluation framework according to an embodiment of the present invention;

[0087] Figure 4 This is a flow chart of importance analysis of an embodiment of the present invention;

[0088] Figure 5 This is a schematic diagram of a component size optimization framework of an embodiment of the present invention;

[0089] Figure 6 : is the finite element calculation result of the drum tower structure of the embodiment of the present invention, wherein (a)-(g) are schematic diagrams of bending moment of bending member, bending moment of compression bending member, shear force of bending member, axial force of compression bending member, member stress distribution, member utilization distribution, and member deformation displacement, respectively;

[0090] Figure 7 The finite element calculation results of the drum tower structure of the embodiment of the present invention (except for the first floor beam);

[0091] Figure 8 Redefine the materials for the embodiments of the present invention;

[0092] Fig. 9 This is a visualization cloud diagram of the importance ranking of components in an embodiment of the present invention, wherein (a) is a cloud diagram of the distribution of key components, and (b) is a cloud diagram of the distribution of various components;

[0093] Fig.10 The stress cloud diagram after optimization of the embodiment of the present invention;

[0094] Fig.11 This is a cloud diagram of utilization after optimization in an embodiment of the present invention;

[0095] Fig.12 This is a schematic diagram of the elevation distribution of the structural component units of the Drum Tower according to an embodiment of the present invention;

[0096] Fig.13 1 is the finite element calculation result of the drum tower structure of the embodiment of the present invention, wherein (a) is the component stress distribution diagram, (b) is the component utilization distribution diagram, and (c) is the component deformation displacement diagram. DETAILED DESCRIPTION

[0097] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0098] The purpose of the present invention is to provide a method and system for parametric design optimization of a drum tower based on structural safety, so as to realize parametric design and structural optimization of the drum tower and improve the safety of the drum tower structure and the economy of materials.

[0099] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0100] Example 1

[0101] The terms involved in this embodiment are explained as follows:

[0102] 1. Component importance calculation method based on component energy method: Component importance calculation based on component energy method is usually completed using the death and life unit function of finite element analysis software. The core of this method is that when a unit fails (i.e. "dies"), its stiffness will drop to near zero, causing the load, stress, strain and other parameters related to the unit to be reset to zero, so that the unit no longer bears load on the structure. This method has been widely used in evaluating the importance of components of concrete frames and masonry structures because it can simulate the brittle failure after the unit is removed.

[0103] However, as an anisotropic and inhomogeneous material, wood usually undergoes plastic deformation when subjected to external forces, which is different from the brittle failure mode simulated by the birth-death unit method. In order to more accurately simulate the mechanical behavior of wood structures, Chunqing proposed an improved method of the birth-death unit method - the "changing elastic modulus method". In this method, the elastic modulus of the unit will be gradually reduced (to 0.05% of its original value, a ratio that has been verified by calculation and can effectively reflect the difference in importance) instead of complete failure. In this way, even the adjusted unit can still transmit force and produce deformation, thereby more realistically simulating the behavior of the wood structure when damaged. This method is not only suitable for the protection of ancient wooden buildings, but also provides an important reference for the maintenance and protection of ancient buildings by evaluating and ranking the importance of components.

[0104] 2. Full stress criterion

[0105] A widely used method in structural optimization design. Its core idea is to ensure that the stress of each component of the structure reaches its allowable limit under at least one working condition, and use this as the optimization target to achieve the lightest weight or lowest cost of the structure while meeting safety requirements. This criterion is particularly suitable for stress-constrained optimization problems, has high computational efficiency, is insensitive to optimization design variables, and is suitable for large-scale topology optimization problems, especially in the optimization design of the smallest volume structure under a single working condition stress constraint.

[0106] 3. Limit state constraints

[0107] According to the clear provisions of the "Uniform Standard for Reliability Design of Building Structures GB 50068-2018", in the process of building structure design, the response and safety of the structure under different limit states must be fully considered to ensure that the building can remain stable and reliable under various possible conditions. In order to achieve this goal, the design work needs to carry out detailed calculations and strict verifications on the performance of the structure under different design conditions. The design conditions of building structures are divided into the following four categories: permanent design, short-term design, accidental design and earthquake design. Structural design should consider different design conditions, based on the corresponding load combinations, and analyze and design for various limit states. According to the requirements of the specification, the design of the ultimate limit state of bearing capacity is the basic and key link. Under the permanent design condition, the design should ensure that when the component reaches the yield point but not the ultimate strength, the structure can remain intact, and its deformation (such as bending) is controlled within the allowable limit to prevent the structural function from being damaged. At the same time, the design of the normal use limit state cannot be ignored, which ensures the normal operation and durability of the structure in daily life. For short-term conditions and earthquake conditions, the design of the normal use limit state also needs to be fully considered to ensure the stability and safety of the structure under extreme conditions.

[0108] Since the performance of components will directly affect the overall safety of the structural system. Through detailed analysis and evaluation of the bearing capacity, stability, fatigue life and deformation capacity of the components under extreme loads, it can be ensured that each basic unit of the structure can maintain its functionality and safety when facing various loads and environmental conditions, thereby ensuring the performance safety of the structure under multiple working conditions. Therefore, according to the relevant provisions of the "Wood Structure Design Standard", this paper extracts the constraint conditions of the components under the limit state:

[0109] (1) Bearing capacity limit state

[0110] Under the ultimate bearing capacity state, the design requirements for the structural components of the Dong Drum Tower are as follows:

[0111] γ0S d ≤R d (3-7)

[0112] Where:

[0113] γ0——Structural importance coefficient, its specific value requirements are shown in Table 1;

[0114] S d — design value of effect of load combination;

[0115] R d ——The design value of the resistance of structural members shall be determined in accordance with the provisions of the "Wood Structure Design Standard".

[0116] The calculation requirements for the design value of the effect controlled by variable loads are as follows:

[0117]

[0118] Where:

[0119] ——Partial coefficient of permanent load, which is 1.2 when the permanent load is unfavorable to the structure and less than 1.0 when it is favorable; ——The partial factor of variable load is 1.4; ——Adjustment coefficient of design service life for variable loads, see the table for the values; ——Load effect value calculated from the standard value of permanent load; ——Load effect value calculated from the standard value of variable load, where It plays a controlling role in the variable load effects; ——Combination value coefficient of variable load; m, n——number of permanent and variable loads participating in the combination.

[0120] The calculation requirements for the design value of effects controlled by permanent loads are as follows:

[0121]

[0122] In the formula, It represents the partial factor of permanent load. When the permanent load is unfavorable to the structure, it is taken as 1.35;

[0123] Table 1 Adjustment factor γ for variable loads considering design service life L

[0124]

[0125] As shown in Table 2, the compression-bending members in the Drum Tower are column members, and the bending members are beams, girders, purlins, etc. The "Wood Structure Design Standard" is an important basis for the design of wood structure projects in my country. The standard is based on probability theory and adopts the limit state design method, providing a scientific and rigorous theoretical system for wood structure design. This embodiment verifies the bearing capacity of bending members and compression-bending members according to the relevant provisions of the standard, thereby providing theoretical guidance for the design and calculation of various components of the Drum Tower.

[0126] Table 2 Component force forms

[0127]

[0128] 1) Design requirements for flexural members

[0129] ① Strength requirements under the ultimate bending bearing capacity state:

[0130]

[0131] Where:

[0132] f m ——Design value of flexural strength of component materials (N / mm 2 );M——Design value of bending moment of bending member (N·mm); W n ——Net section resistance moment of bending member (mm 3 );

[0133] ② Strength requirements under the ultimate state of shear bearing capacity:

[0134]

[0135] Where:

[0136] f V ——Design values ​​of bending strength and shear strength along the grain of component materials (N / mm 2 ) ; V—— design value of shear force of bending member (N); I—— moment of inertia of the full section of the member (mm 4 ); b——the cross-sectional width of the component (mm); S——the area moment of the cross-sectional area above the shear plane about the neutral axis (mm 3 );

[0137] ③ Stability requirements under the ultimate bearing capacity state:

[0138]

[0139] In the formula, ——lateral stability factor of bending members;

[0140] 2) Design requirements for compression-bending members

[0141] ① Strength requirements under the ultimate bearing capacity state:

[0142]

[0143] Where, N is the design value of axial pressure (N); M0 is the design value of the maximum initial bending moment at mid-span under lateral load (N mm); A n ——Net cross-sectional area of ​​the component section (mm 2 );W n ——Calculate the full section resistance moment of the component (mm 3 ); e0——initial eccentricity of the axial pressure of the component (mm); if uncertain, it shall be 0.05 times the cross-sectional height of the component; f c 、f m ——Design values ​​of tensile strength and flexural strength along the grain of the component material after considering the adjustment coefficient (N / mm 2 ).

[0144] ② Stability requirements under the ultimate bearing capacity state:

[0145]

[0146] Where: ——Stability factor of axially compressed members and reduction factor considering the combined effect of axial force and initial bending moment; A0——Calculation area of ​​member cross section (mm 2 ).

[0147] (2) Normal use limit state

[0148] Under the normal use limit state, the design requirements of the structural components of the Dong ethnic group drum tower are as follows:

[0149] S d ≤C (3-15)

[0150] Where, C is the specified limit value for the structure or component to meet normal use requirements, determined according to the "Wood Structure Design Standard";

[0151] Effect design value S of standard load combination d The calculation should be carried out as follows:

[0152]

[0153] 1) Design requirements for flexural members

[0154] Deformation requirements under normal use limit state:

[0155] ω≤[ω] (3-17)

[0156] Where, ω is the deflection calculated using the standard load combination under the serviceability limit state design of the member (mm); [ω] is the deflection limit of the bending member (mm).

[0157] 2) Design requirements for compression-bending members

[0158] Lateral stability requirements outside the plane of bending moment:

[0159]

[0160] Where: M is the design value of the bending moment in the bending plane (N mm); W is the net section resistance moment of the calculated component (mm 3 );f c 、f m ——Design values ​​of tensile strength and flexural strength along the grain of the component material after considering the adjustment coefficient (N / mm 2 ); ——lateral stability factor of bending members; ——The axial compression rod is perpendicular to the plane of the bending moment according to the slenderness ratio λy Determine the stability factor of the axial compression rod;

[0161] The above design requirements for key indicators such as strength, stability and deflection of components can be used as constraints for the optimization method of this embodiment, so as to ensure that the components can meet the safety verification requirements in practical applications. First, the strength constraint focuses on the bearing capacity of the component when subjected to external forces, ensuring that the component will not be damaged under the most unfavorable load combination. This includes the analysis of the cross-sectional dimensions, material properties and force paths of the component, as well as the calculation of possible shear forces, bending moments and axial forces, so as to obtain the stress distribution and bearing potential of the component under different loads. The stability constraint focuses on the lateral behavior of the component when under compression, especially under complex loads, such as wind loads or eccentric loads, which may lead to the risk of component instability. This involves a comprehensive consideration of the geometry, support conditions and material properties of the component, as well as the prediction of critical loads and deformation capacity, to ensure that the component can remain stable under various working conditions. The deflection constraint focuses on the degree of deformation of the component under load, especially in the case of long-term use and repeated loads, excessive deflection may reduce the functional performance of the building structure.

[0162] 4. Anti-overturning restraint

[0163] As a high-rise building with a large height-to-width ratio, the Dong Drum Tower is subject to a large horizontal wind load, and the overall anti-overturning calculation of the structure should be carried out to judge the safety of the overall structure. Since the current "Wood Structure Design Standard" does not have specific provisions for the anti-overturning calculation of wooden buildings, this embodiment draws on the overall structural overturning calculation method of the "Technical Code for Concrete Structures of High-rise Buildings", see formula 3-4:

[0164] M 抗(永久荷载+0.5活荷载) / M 倾(水平荷载设计值) ≥1.0 (3-4)

[0165] Formula "M 抗(永久荷载+0.5活荷载) / M 倾(水平荷载设计值) ≥1.0” means that the anti-overturning moment of the structure must be greater than or equal to the moment that causes overturning to ensure the stability of the structure; a ratio greater than 1.0 indicates that the structure has sufficient safety to resist potential overturning risks.

[0166] Where M 抗MomentResisting refers to the moment that the structure itself can resist overturning. It is usually generated by the weight of the structure (permanent load) and part of the live load (variable load). When calculating the anti-overturning moment under earthquake action, the live load takes the combination coefficient of the gravity load representative value combined with the earthquake action 0.5 (i.e. D+0.5L); and when calculating the anti-overturning moment under wind load, the live load takes the combination value coefficient 0.7 (i.e. D+0.7L). So M 抗(永久荷载+0.5活荷载) It represents the anti-overturning moment generated by the combined action of permanent load and part of live load. 倾 It refers to the overturning moment, that is, the moment that causes the structure to overturn, usually caused by wind load, earthquake or other horizontal loads; the horizontal load design value refers to the horizontal force of wind load or earthquake considered during the design, which is calculated based on local building codes and specific conditions of the structure.

[0167] Based on research results and engineering application experience, Xu Peifu summarized the calculation formulas for overturning moment and anti-overturning moment in "Structural Design of Complex High-Rise Buildings":

[0168] 1) Overturning moment

[0169] Assuming that the overturning moment calculation surface is the foundation bottom surface, and the force of the overturning moment calculation is the horizontal earthquake action or the standard value of the horizontal wind load, the overturning moment is:

[0170] M OV =V0(2H / 3+C) (3-5)

[0171] Where: M OV ——Standard value of overturning moment; H——Height of the building above the ground, i.e., building height; C——Basement depth; V0——Standard value of total horizontal force.

[0172] 2) Anti-overturning moment

[0173] The calculation point of the anti-overturning moment is assumed to be the outer edge point of the foundation, and the calculation force of the anti-overturning moment is the representative value of the total gravity load. The anti-overturning moment can be expressed as:

[0174] M R =GB / 2 (3-6)

[0175] Where: M R ——Standard value of anti-overturning moment; G——Representative value of total gravity load of upper and basement foundation (standard value of permanent load + 0.5 standard value of live load); B——Width of bottom surface of basement foundation.

[0176] 5. Stability verification coefficient formula

[0177] The stability factor of axially compressed members is calculated according to the following formula

[0178]

[0179]

[0180] When λ>λ c hour:

[0181] When λ≤λ c hour:

[0182] Where:

[0183] λ——slenderness ratio of compression member; i——radius of gyration of member section (mm); l0——calculated length of compression member (mm), determined according to relevant provisions of “Wood Structure Design Standard”; f ck ——Standard value of compressive strength of materials of compression components (N / mm 2 );E k ——Standard value of elastic modulus of component material (N / mm 2 );a c 、b c 、c c ——Material correlation coefficient, determined in accordance with the relevant provisions of the "Wood Structure Design Standard"; β——Material shear deformation correlation coefficient, determined in accordance with the relevant provisions of the "Wood Structure Design Standard".

[0184] The lateral stability factor of the bending member is calculated according to the following formula:

[74] :

[0185]

[0186] When B >λ m hour:

[0187] When B ≤λ m hour:

[0188] In the formula, λ B ——The slenderness ratio of bending members should not be greater than 50; e ——Calculated length of the bending member (mm), determined according to the relevant provisions of the "Wood Structure Design Standard"; b——Cross-sectional width of the bending member (mm); h——Cross-sectional height of the bending member (mm); f mk ——Standard value of bending strength of bending member materials (N / mm 2 );a m 、bm 、c m ——Material correlation coefficient shall be determined in accordance with the relevant provisions of the “Wood Structure Design Standard”.

[0189] The reduction factor considering the combined effect of axial force and initial bending moment is calculated according to the following formula:

[0190]

[0191]

[0192]

[0193] Where A is the calculated area of ​​the component cross section (mm 2 ); In Karamba, it is reflected as the material utilization rate of the component under axial pressure. It is the material utilization rate of the component under the action of bending moment, which can be obtained from the Utilization of Elements output port in Karamba3D.

[0194] like Figure 1 As shown, a parametric design optimization method for a drum tower based on structural safety is provided in an embodiment of the present invention, comprising the following steps:

[0195] S1. Construct a Drum Tower axis model, and import the Drum Tower axis model into the Drum Tower Rhino & Grasshopper parametric platform to obtain a parametric geometric model with adjustable size;

[0196] S2. Setting analysis parameters on the Gulou Rhino&Grasshopper parametric platform, wherein the analysis parameters include vertical load, wind load, material properties, section size, nodes and constraints, and obtaining key performance indicators of the Gulou under load conditions through analysis on the Gulou Rhino&Grasshopper parametric platform, wherein the key performance indicators include internal force, stress, deflection, material utilization, stability and strength;

[0197] S3. Based on the key performance indicators, a component importance calculation method is used to automatically locate key components in the structure of the Drum Tower (key components include all wooden component units, beams, columns, and rafters of the Drum Tower), and a component importance distribution cloud map is generated to visualize the component importance;

[0198] S4. Optimizing the size of the key component according to the full stress criterion to obtain the minimum cross-sectional size of the optimized component under the ultimate strength bearing capacity state;

[0199] S5. Based on the minimum cross-sectional size, the load effect values ​​under the ultimate bearing capacity state and the normal use limit state are used to verify the anti-overturning, stability and deflection of the optimized components. If the verification results meet the corresponding constraints, it means that the structural optimization of the Drum Tower is successful, and the optimization results are visualized. After optimization, the structural indicators of component stress, deflection and material utilization will all decrease, and the volume of structural materials and the weight of the structure will be greatly reduced.

[0200] In this embodiment, Figure 2 As shown, the S1, constructs a Drum Tower axis model, and imports the Drum Tower axis model into the Drum Tower Rhino & Grasshopper parametric platform to obtain a parametric geometric model with adjustable size, specifically including:

[0201] S101. Define the Drum Tower model units (including beams, columns, and rafters): Build an axis model, accurately identify and extract the intersection points of the axis; then, divide the axis through these intersection points to generate beam unit line segments. By importing these line segments into the parametric platform panel, you can intuitively see the position and direction of each beam unit in three-dimensional space, and obtain key information such as its length, size, and bending stiffness, so as to perform accurate linkage analysis.

[0202] S102, generate geometric model: adopt parametric design method, import the three-dimensional axis model of drum tower into the Dong ethnic drum tower parametric platform interface. The platform can automatically identify the spatial coordinates of the model, match the corresponding component unit name according to the axis information, and then automatically give the component accurate three-dimensional size data to form a parametric geometric model with adjustable size.

[0203] In this embodiment, in S2, the analysis parameters specifically include:

[0204] Load - Refer to the relevant provisions of the "Building Structure Load Code" to determine the standard values ​​of various types of dead loads and live loads. The values ​​of the structure's deadweight and floor live loads can be found in the relevant specifications.

[0205] Material properties - In Karamba3D, you can use the preset parameters in the built-in library to set wood properties, or you can customize them according to the wood structure design standards and relevant Chinese specifications. Custom wood properties allow users to manually enter relevant parameters to ensure accurate properties and design safety.

[0206] Section size--Karamba3D, as a building structure analysis plug-in integrated into the Rhino&Grasshopper platform, provides powerful tools to set and manage the cross-sectional shape and size of components. For different types of components, such as columns, purlins, rafters and beams, select the appropriate cross-sectional shape according to the actual application scenario. For example, columns and purlins usually use circular tube sections because this shape has good stability and bearing capacity when subjected to axial pressure and bending moment. Beams are more suitable for trapezoidal solid sections because this section shows high stability and efficiency when subjected to shear force and bending moment. .

[0207] Nodes and Constraints - In Karamba3D, finite element models can be constructed to simulate complex node connections. By default, nodes are defined as fully rigid connections; properly defined supports are essential to maintain the stability of the structure under load. The "Support" operator in Karamba3D provides six different types of fixation, corresponding to the global X, Y, and Z axes of translation and rotational freedom. By clicking on the six small dots on the "Support" operator, the state of these fixations can be modified to accurately simulate the boundary conditions of the structure. In order to ensure the accuracy of the simulation, the specific stiffness coefficients should be determined based on experimental data or verified simulation values, so as to more realistically reflect the behavior of the structure under actual working conditions.

[0208] Visual analysis of results - Karamba3D displays the analysis results in a variety of forms, such as 3D cloud maps and data tables, to intuitively understand the distribution of structural parameters such as displacement, stress, and strain.

[0209] By setting the above analysis parameters, it is ensured that the geometric structure of the model can be accurately converted into the finite element model in Karamba3D.

[0210] In this embodiment, Figure 3-4 As shown, S3, based on the key performance indicators, uses a component importance calculation method to automatically locate key components in the structure of the Drum Tower (key components include all wooden component units, beams, columns, and rafters of the Drum Tower), and generates a component importance distribution cloud map to visualize the component importance, specifically including:

[0211] Component importance evaluation is an evaluation of each component in the engineering structure. It mainly includes three core modules: component unit redefinition, unit importance calculation and importance ranking visualization.

[0212] First, component unit redefinition is the process of classifying and describing each component in the engineering structure. This process mainly includes two aspects: first, redefining the material properties of the component to facilitate subsequent calculation and analysis of the contribution of the component to the overall structure; second, describing the position, function, stress condition, etc. of the component in the structure in detail to facilitate understanding of its role in the entire structure.

[0213] Secondly, the calculation of unit importance is the key link to evaluate the importance of each component. This part of the work is mainly based on the component importance evaluation method of energy flow, which comprehensively considers the basic properties of the component, the stress condition and engineering experience, and quantifies the importance of the component. This process requires full use of the knowledge and experience of engineering structures to ensure the accuracy and reliability of the evaluation results.

[0214] Finally, the importance ranking visualization module displays the calculated component importance index in an intuitive way, which helps designers quickly understand and grasp the importance of each component in the structure. This part of the work mainly ranks and marks the importance of components through charts, colors, etc.

[0215] In this embodiment, the S4, optimizing the size of the key component according to the full stress criterion to obtain the minimum cross-sectional size of the optimized component under the ultimate strength bearing capacity state, specifically includes the following steps:

[0216] In the optimization process, the first step is to set a sequence of component sizes arranged from small to large, and input it into the parametric finite element analysis program as a design variable (using the RH&GH platform to input parameters). Under the premise of satisfying the rationality of the node connection, follow the full stress design principle and use the optimized cross-section operator to perform iterative calculations to determine the minimum applicable cross-sectional size of the component. Then, the safety indicators of the optimized and adjusted components and the overall structure are verified. If the verification results show that the safety requirements are met, the current cross-sectional size can be determined as the optimal solution; otherwise, if it is not met, the range of the cross-sectional size must be readjusted, such as Figure 5 shown.

[0217] The process also includes: setting of analysis conditions and optimization of cross-section calculations;

[0218] Regarding the analysis condition setting: In the process of optimizing the component size, the input port of the operator needs to be accurately configured. This includes the definition of design variables, the clarification of optimization goals, and the setting of constraints to ensure that the optimization task is automatically and intelligently executed.

[0219] (1) Set design variables - component cross-sectional dimensions list

[0220] The list of component cross-sectional dimensions contains the component cross-sectional dimensions arranged in order from small to large. The given size range is set as the parameter value domain of the design variable to ensure that all possible solutions can be fully explored during the optimization process. In addition, when setting the size range, the restrictions of the mortise and tenon structure on the shape and size ratio of the components need to be considered to ensure that there will be no unreasonable structural nodes such as the thickness of the beam exceeding the diameter of the column. Based on the geometric size constraints of the components, a suitable list of component cross-sectional dimensions can be created in Karamba3D.

[0221] (2) Setting optimization goals - material utilization

[0222] In Karamba3D, stress criteria are reflected in the settings of material strength and utilization. In the finite element analysis module, the strength design values ​​of various materials have been set in accordance with relevant specifications. In the component size optimization module, the material utilization is used as a control parameter. When it reaches 100%, it means that the component has reached the full stress design state. To do this, the parameter setting value needs to be input into the Maximum utilization port of the Optimize Cross Section operator.

[0223] (3) Setting constraints - component safety indicators

[0224] By designing constraints based on the limit state, a series of indicators for judging the safety of components can be established. Based on the Grasshopper platform and Python language, the algorithmic expression and automatic calculation of these design constraints are realized. First, the cross-sectional dimensions of the components are optimized through the Optimize Cross Section operator in Karamba3D. The optimized mathematical model for the size optimization of the drum tower components will output key mechanical parameters, such as axial force, bending moment and shear force, which are the basis for subsequent strength, stability and deflection verification. Subsequently, these mechanical analysis values ​​are input into the previously written program, and a series of verification calculations are performed on the components according to the limit state design principles.

[0225] (4) Set the number of iterations

[0226] The number of iterations can be set in the input port of the Optimize Cross Section component according to actual needs. After the default 5 iterations, if the optimization result still does not reach the expected stability or accuracy, it usually means that the number of iterations needs to be increased, so that a more suitable solution may be found.

[0227] (5) Set optimization strategy

[0228] Based on the results of finite element analysis, not only can we understand the stress distribution and potential fatigue damage areas of each component in detail, but also can serve as data support for evaluating the importance of components, thereby providing a scientific basis for the formulation of structural optimization strategies. In the formulation of optimization strategies, the principle of differentiation is crucial. For components with excessively high material utilization, the traditional principle of economy may no longer apply. In this case, structural safety performance should be given priority, and the bearing capacity and durability of these components should be improved by increasing the cross-sectional size to ensure the stability and safety of the entire structure. In addition, by sorting the importance of components, the key and secondary components in the structure can be accurately identified. This sorting allows the optimization work to be targeted and give priority to those components that have the greatest impact on structural safety and performance. This not only improves the efficiency of optimization, but also ensures the rational allocation and use of optimization resources.

[0229] About optimizing cross-section calculations: In the field of structural engineering, optimizing the cross-sectional dimensions of beams is of great significance for improving material efficiency and meeting structural performance requirements. The "Optimize Cross Section" operator in Karamba3D software can automatically determine the optimal cross-sectional dimensions of beams through an iterative algorithm based on a preset cross-sectional dimension range. This process aims to maximize material utilization while taking into account a variety of mechanical effects including normal force, biaxial bending, shear and torsion to ensure that the selected section achieves optimal material utilization while meeting structural safety requirements. The optimization process follows the following steps:

[0230] (1) Model input and preparation: First, the structural model data processed by the "Analyse" operator is sent to the "Optimize Cross Section" operator through the Model port. Then, specific components are selected for optimization through the Elem and Group ports to ensure that the cross-sectional dimensions of these components match the design specifications.

[0231] (2) Optimization target setting: The maximum material utilization rate of the component is specified through the Maximum utilization port, which reflects the stress distribution state of the component and serves as the full stress criterion optimization standard in the optimization process.

[0232] (3) Section design within the elastic range: The operator works under the default activation of the Elast (elastic modulus of the material) port to ensure that the section design process is carried out within the elastic range of the material. If the load on the model exceeds the load-bearing limit of the cross-section series, the system will issue a warning through the Info (detailed information of the model) port to indicate potential risks.

[0233] (4) Input of cross-section set: The cross-section size set is input through the CroSecs (cross-section property of structural components) port. The set is sorted according to the cross-section height or area size, and the optimal size set under the current target performance is calculated through iteration to achieve effective use of materials under the premise of safety.

[0234] (5) Optimization process: The optimization operator gradually approaches the optimal solution through an iterative method. In the initial stage, the initial cross-sectional dimensions are used at the key positions of the beam to determine the cross-sectional stress conditions. Subsequently, the minimum cross-sectional dimensions that meet the requirements are selected from the cross-sectional dimension set of each component. The optimization process ends when all components do not need further adjustment or the preset upper limit of the number of iterations is reached. If further optimization is required, the operator will repeat the above steps using the newly selected cross-sectional dimensions.

[0235] (6) Result verification and convergence: In order to verify the effectiveness and convergence of the optimization results, the "Utilization of Elements" operator can be used to check the utilization of each component. This verification step ensures that the optimization process can achieve the set goal within the specified number of iterations, thereby obtaining the optimal cross-sectional size set that minimizes the amount of structural material used.

[0236] In this embodiment, S5, based on the minimum cross-sectional size, the load effect values ​​under the ultimate bearing capacity state and the normal use limit state are used to verify the anti-overturning, stability and deflection of the optimized component. If the verification results meet the corresponding constraint conditions, it indicates that the structural optimization of the drum tower is successful, and the optimization results are visualized, specifically including:

[0237] 1) Anti-overturning calculation: According to the anti-overturning constraint formulas 3-4 to 3-6 in the glossary, edit the program in Grasshopper to perform anti-overturning calculations on the entire structure. The required calculation values ​​in the formula can be retrieved from the calculation results of the finite element analysis module.

[0238] 2) Stability verification: In Karamba3D, finite element calculation is performed on the load effect value of the structure under the ultimate bearing capacity state. In Grasshopper, the stability coefficient φ of the axial compression member and the lateral stability coefficient φ of the bending member are calculated according to formulas 4-1 to 4-11. l and the reduction factor φ considering the combined effect of axial force and initial bending moment m , then substitute the stability coefficient and reduction factor into the stability constraint formula 3-7 of the compression-bending member, and in Grasshopper, determine whether each type of member meets the stability constraint.

[0239] After clarifying the value selection methods of each parameter in these formulas, the stability coefficient φ of axially compressed members and the lateral stability coefficient φ of bending members can be calculated. l , and the reduction factor φ m , and based on the stability constraint conditions of compression-bending and bending members in the glossary, Formula 3-7, Formula 3-8 and Formula 3-10, the stability of compression-bending members and the lateral stability outside the moment action plane and the stability of bending members are verified in Grasshopper respectively.

[0240] 3) Deflection verification: The deflection verification module focuses on the deformation level of the structure under the normal service limit state. Using Karamba3D for finite element analysis, the expected deformation of the component can be calculated and obtained by applying the load under the normal service limit state. These calculation results are then used for deflection verification in Grasshopper. This process can systematically check the deflection of the bending member according to the given deflection limit standard, as shown in Table 3.

[0241] Table 3 Deflection limits of flexural members

[0242]

[0243] 4) Result visualization and theoretical size range verification

[0244] The results visualization displays the output of the optimized cross-sectional size module. The cross-sectional parameters of the component, including diameter, width, height, and area, are displayed through the output interface for intuitive evaluation. At the same time, when verifying the stability and deformation of the structure, the component outputs the verification results of each component in the form of Boolean logic values ​​(True or False) to intuitively indicate whether the design criteria are met. When the verification results show a False value that does not meet the requirements, this usually indicates that the minimum value of the component cross-sectional size needs to be adjusted. By increasing the minimum cross-sectional size, the iterative optimization process can be continued until all outputs of the verification submodule are True, ensuring that all components meet the stability and deformation constraints. After reaching this state, the determined component cross-sectional dimensions and the overall structural material volume represent the optimal design solution under the given constraints.

[0245] Taking into account the actual engineering construction needs of the Dong ethnic group drum tower and the prospects for the assembled and modular construction of the drum tower, the present invention is able to determine the optimal size solution that strikes a balance between safety and economy. However, the size provided by the scheme is a static fixed value, and its applicability in practical applications is limited. In order to improve the practicality of the optimization scheme, this embodiment proposes to add a theoretical size verification module to the existing program. This module will use the theoretical size range of the main components under modularization determined in the following table as the variable set, and use 10 mm as the step size for iterative calculation, in order to verify the accuracy of the theoretical size. In this embodiment, the theoretical size range of the main structural components of the drum tower is as follows:

[0246] Table 4 Theoretical size range of main structural components of Drum Tower based on modularization

[0247]

[0248] Based on the results of iterative calculations, the theoretical dimensions under modularization are further verified for safety to determine the lower limit of structural safety. When the size of the component is lower than the lower limit, it can be determined that the Drum Tower design has safety hazards. By defining the unsafe size range, we can further screen and exclude those modular design solutions that may bring safety risks, providing certain technical support for the modular construction of the Drum Tower in the future.

[0249] In this embodiment, the Rhino&Grasshopper parametric platform may also be replaced by other parametric platforms such as nTopology.

[0250] Example 2

[0251] This embodiment takes the Wu Liuxiong Drum Tower in Guangxi Zhuang Autonomous Region as an example to further illustrate the parametric design optimization method of the Drum Tower based on structural safety described in Embodiment 1.

[0252] 1. Case model selection and model mapping data

[0253] Wu Liuxiong Drum Tower in Guangxi Zhuang Autonomous Region was selected as a case study object. It is located in Gaoding Village in the northern mountainous area of ​​Dudong Town, Sanjiang County, Guangxi Zhuang Autonomous Region, my country. According to the "Gaoding Dong Village Cultural and Historical Materials", Wu Liuxiong Drum Tower was first built in 1986. However, the building encountered structural problems shortly after its completion, including foundation subsidence, building tilt, and serious damage to components such as building columns and beams. In view of this, the structure of the drum tower was optimized; its drawings and design parameters were determined through surveying and mapping.

[0254] 2. Set the analysis model and analysis parameters

[0255] (1) Constructing the analysis model

[0256] Generate geometric model - using parametric design method, import the three-dimensional axis model of Wu Liuxiong's Drum Tower into the Dong Drum Tower parametric platform interface. The platform can automatically identify the spatial coordinates of the model, match the corresponding component unit name according to the axis information, and then automatically assign accurate three-dimensional dimension data to the component to form a parametric geometric model with adjustable size; define the model unit - the construction of the axis model, accurately identify and extract the intersection points. Subsequently, the axis is divided by these intersections to generate beam unit segments. By importing these segments into the parametric platform panel, the position and direction of each beam unit in three-dimensional space can be intuitively seen, and key information such as its length, size, bending stiffness, etc. can be obtained, so as to perform accurate linkage analysis.

[0257] (2) Setting analysis parameters

[0258] Vertical load - In the design of building structures, accurate calculation of loads is crucial to ensure structural safety. Loads are divided into two categories: permanent loads and variable loads. Permanent loads mainly come from the weight of the structure and the weight of building materials. Through research, it was learned that the roof material of Wu Liuxiong Drum Tower is small green tiles, and the floor material is hardwood. According to the provisions of the "Code for Loads on Building Structures GB 50009-2012" on the self-weight per unit volume of commonly used materials and components, the specific value of permanent loads can be calculated. Variable loads include but are not limited to floor live loads and snow loads. For floor live loads, it can be defined by referring to the standard value of uniformly distributed live loads on floors of civil buildings in the code. As for the calculation of snow loads, it needs to be determined according to geographical location and climatic conditions. According to the national basic snow pressure distribution map, the basic snow pressure in Sanjiang County for 50 years is 0.2kN / m2. Considering that the slopes of the Drum Tower's roof and the small green tile roof are 24° and 43° respectively, the corresponding snow distribution coefficients can be used, which are 1.0 and 0.46 respectively. By applying Formula 3-20, the standard value of snow load on the Drum Tower can be calculated. In order to ensure the accuracy and reliability of the structural design, it is necessary to organize the load standard value, combination value coefficient, sub-item coefficient and age adjustment coefficient into a table, as shown in Table 5. These data will serve as the basic data for structural analysis and design in Karamba3D. In Karamba3D, different working conditions can be set according to these basic data to simulate and analyze the behavior and response of the structure under various load combinations.

[0259] The standard value of snow load on the horizontal projection surface of the roof should be calculated as follows:

[0260] s k =μ r s0 (3-20)

[0261] Where: s k Indicates the standard value of snow load (kN / m2); μ rIt represents the snow distribution coefficient on the roof; s0 represents the basic snow pressure (kN / m2).

[0262] Table 5 Vertical load setting table

[0263]

[0264] Wind load - According to the 3-20 wind load calculation method, after inputting the necessary parameters into the wind load simulation module interface, the program can automatically calculate the wind load values ​​of the drum tower at different heights and windward surfaces. According to the research results of "Study and Analysis on Wind-Induced Structural Safety of Dong Nationality Wooden Drum Tower in Southeast Guizhou", the most unfavorable wind direction angle for the displacement response of the drum tower is 0°, that is, the displacement of the drum tower under the wind load at a wind direction angle of 0° is more significant than that at a wind direction angle of 45°. Based on this, this module sets the set wind direction angle of the wind load to 0°, and lists in detail the wind load parameters of each simulation point on the windward side of Wu Liuxiong's drum tower at a wind direction angle of 0°.

[0265] Material properties - Gao Ding Wu Liuxiong The wood used for the Drum Tower is local fir, including logs and square timber. According to the relevant provisions of my country's "Wood Structure Design Standard", the strength design value and elastic modulus of fir should be set according to the standard of TC11 A wood. In addition, according to the provisions of the standard on the strength grade adjustment coefficient, the strength design value and elastic modulus of the load-bearing materials of wooden buildings should be multiplied by the adjustment coefficients of 0.9 and 1 respectively.

[0266] Section size - The axis of the Wu Liuxiong Drum Tower obtained by the parametric generation module is used as the modeling axis of the rod unit, and the floor plane is used as the modeling plane of the lattice shell unit. Line to Beam and Mesh to Shell are used in Karamba3D to construct rod units and lattice shell units. According to the cross-sectional size of the components obtained from the survey, the corresponding component unit form is set in the platform.

[0267] Nodes and constraints - The mortise and tenon joints are assumed to be completely rigid connections, and the vertical and horizontal linear displacement constraints of the column base nodes can be ignored to simplify the mechanical model of the structure.

[0268] Finite element calculation results: After adding the wind load condition, the finite element module calculates and the bending moment diagram and shear force diagram of the bending member, the bending moment diagram of the compression bending member, the axial force size, stress distribution, utilization rate distribution and deformation displacement diagram of the overall frame rod can be interactively observed through the visualization module, such as Figure 6As shown in Figure (a), the maximum bending moment is located at the intersection of the first-floor middle column and the four middle columns, and its values ​​are 1.355kN·m and -1.366kN·m respectively; as shown in Figure (b), the maximum compression bending moment is located at the intersection of the long melon column of the building and the middle column with the middle column, and its values ​​are 0.314kN·m and -2.233kN·m respectively; as shown in Figure (c), the maximum shear force of the bending member is located at the intersection of the melon column of the building and the through-beam of the same layer and the first-floor middle column, and its values ​​are 1.418kN and -1.049kN respectively; as shown in Figure (d), the maximum axial force of the member is located at the eaves column, and its values ​​are 2.071kN and -1.603kN respectively.

[0269] As shown in Figures (e) and (f), the maximum stress and utilization rate are located at the intersection of the building body columns and the beams on the same floor, and their values ​​are 0.702 kN / m 2 、-0.691kN / m 2 and 104.0%; Figure (g) shows that the maximum displacement is located at the purlin on the first floor of the building, and its value is 1.31cm. The calculation results show that under the current working conditions and materials, the stress at the intersection of the building column and the same floor through-beam exceeds the yield stress of fir, and there is a possibility of component damage. Therefore, it is necessary to consider increasing the cross-sectional size of the through-beam at this location to cope with the current load. In addition, Figure 5-12 It can be seen that, except for the beams on the first floor, the maximum utilization rate of the remaining components is only 69.5%, which is far from meeting the requirements of the current working conditions. It is possible to consider reducing the cross-sectional size of such components to reduce the material cost. The weight of the structure before optimization is 12164.3kg, and the material volume is 30.4m 3 .

[0270] 3. Component importance evaluation

[0271] According to the results of the finite element analysis of the Drum Tower structure, it can be found that under the action of a wind load of once in 50 years, some components of the Drum Tower have reached their yielding state, and there is a possibility of component damage. In this case, it is not practical to verify the bearing capacity of the components because the structure is already close to the critical point of its performance. Therefore, this module chooses to focus on the importance analysis of the components so that in the subsequent size optimization stage, the bearing capacity evaluation can be used as a key structural constraint in the optimization process. This approach not only ensures that the consideration of structural safety is incorporated into the optimization design, but also helps to achieve the best balance between structural performance and material economy.

[0272] First: Redefinition of component units

[0273] Under the condition of keeping the rest of the fir material properties constant, the elastic modulus of fir needs to be adjusted to 0.05% of its initial value. This adjustment will be applied to each component unit one by one to achieve the redefinition of its properties. In the process of redefining a single component, it is necessary to ensure that the elastic modulus of the materials of other components remains unchanged from its original value. In order to verify whether the component material properties have been successfully redefined, the "Model View" operator can be used to perform a real-time check by using the amplified deformation coefficient function. This function can intuitively observe the deformation of the component under the action of force, so as to determine whether its elastic modulus has reached the expected value. In this way, any property adjustment that does not meet the design requirements can be discovered and corrected in time to ensure the stability and performance of the entire structure to reach the optimal state.

[0274] Second: Unit Importance Calculation

[0275] After calculating the importance of the structural components of Gao Ding Wu Liuxiong's Drum Tower, the calculation results show that the importance of the first-floor central column and the beam ranks first, because it not only constrains the four central columns, but also bears the function of transferring the loads of the floor slab and the floor sleepers. In addition, the importance of the Leigong column and the Taiping beam is also quite significant, due to their key role in the load transfer process of the Drum Tower's top, which has a core influence on the stability of the overall structure. At the same time, the central column and the eaves column have a high component importance due to their significant role in the vertical load transfer; the central column is similar to the core tube structure in a high-rise building, which plays a key supporting role in the stability of the overall structure, and the eaves column, in addition to bearing the vertical load, also needs to resist the horizontal wind load, which further enhances its importance in the structure.

[0276] Third: Visualization of Importance Ranking

[0277] (1) Key components

[0278] The total number of Wu Liuxiong Drum Tower component units involved in the calculation is 232. According to the importance level assessment method of the Dong Drum Tower, these key components mainly include the first-floor central column, the Leigong column, the Taiping beam, the central column and the main beam. Fig. 9 (a) As shown. Maintenance managers need to pay close attention to these components and take appropriate protective measures. It is recommended to regularly check the integrity of these components and take immediate repair or replacement measures if any signs of damage are found to ensure the long-term stability and safety of the structure.

[0279] (2) Order of importance

[0280] By conducting an in-depth analysis of the ranking of the component importance calculation results, the designer can clearly determine the distribution of key components, secondary components and general components in the Drum Tower, such as Fig. 9This distribution map provides an important reference for the protection and management of the Drum Tower, helping users to more accurately understand the importance of each component and thus formulate more scientific and reasonable protection and management strategies.

[0281] In addition to the key components mentioned above, the secondary components mainly include the purlins of the building and the central column beams. These components play a pivotal role in the structure of the Drum Tower. Although their importance is slightly inferior to that of the key components, they have an impact on the stability and service life of the Drum Tower that cannot be ignored. Therefore, in the protection of the Drum Tower, the maintenance and management of the secondary components also need to be given enough attention.

[0282] 4. Component size optimization procedure

[0283] The component size optimization process follows the following steps: (1) Formulate a size optimization strategy based on the calculation results of material utilization and component importance; (2) Provide a component cross-sectional size set as a design variable to define the geometric size constraints of the component; (3) Determine the optimized structural material volume setting as the optimization target, clarify the full stress criterion as the optimization principle, and adjust the component cross-sectional size through a computer iterative method to obtain the optimized solution; (4) Verify the optimization results to ensure that the component meets the constraints of stability and deflection.

[0284] First: Set the optimization factor

[0285] In view of the complexity of the Drum Tower structural system and the large number of its components, this embodiment selects to optimize the cross-sectional dimensions of the main structural components such as columns, beams, purlins, etc. Based on the actual dimension value of Wu Liuxiong's Drum Tower fluctuating by 35% (determined according to the theoretical dimension range), the dimension range of the component is defined, and the specific dimension variable range is listed in Table 6.

[0286] Finally, based on the results of finite element analysis and the calculation of component importance, the following optimization strategies are formulated: for the first-floor crossbeam with weaker structural performance, and the five key components of the first-floor middle column, the purlin, the thunder column, the Taiping beam, the middle column and the main beam that contribute greatly to the overall structure, the optimization measures of increasing the cross-sectional size are adopted, aiming to improve the bearing capacity and the overall stability of the structure by increasing the cross-sectional size of the key components; for other components, the optimization strategy of reducing the cross-sectional size is adopted to reduce the deadweight of the structure, reduce material consumption, and maintain the safety and functionality of the structure. In addition, considering the size constraints, for the first-floor crossbeam that needs to increase the cross-sectional size, the corresponding supporting measures are also proposed in this embodiment, that is, the cross-sectional size of the eaves column, the hanging column and the first-floor body melon column that intersects with it is increased at the same time, so as to ensure that the intersection of the column and the crossbeam will not cause cracks due to unreasonable size ratio design.

[0287] Table 6 Component cross-sectional dimension variable range

[0288]

[0289]

[0290] Although the above optimization results can achieve a balance between structural safety and economy and obtain the optimal size set. However, it is necessary to determine a safe scale range in combination with the parametric design of the Drum Tower and the engineering construction requirements. Therefore, the modulus relationship of the Drum Tower components and the theoretical value range of the melon column diameter established the theoretical size range of the main structural components of the Drum Tower based on the modulus. In order to ensure the accuracy and comprehensiveness of the analysis, a detailed division was adopted with a step length of 10 mm, so as to conduct a detailed analysis and evaluation of the structural safety of the Drum Tower.

[0291] At the same time, in order to ensure the adequacy of the optimization process and the reliability of the results, the number of iterations was set to 20. This setting allows the algorithm to have enough opportunities to explore the possible solution space to find the optimal cross-sectional size. At the same time, the setting of the aspect ratio helps to maintain the rationality of the cross-sectional shape, thereby ensuring the stability of the performance of the structure under stress. By adjusting the size range while maintaining the aspect ratio, it can be ensured that the optimized cross-section not only meets the requirements of structural performance, but also effectively reduces material costs.

[0292] Second: Optimization results analysis

[0293] The output of this module provides a wealth of information, including the total weight of the optimized structure, the total material usage, the optimization efficiency, and the cross-sectional dimensions of each component. These data not only intuitively demonstrate the optimization effect, but also provide a detailed basis for subsequent structural analysis and evaluation. Fig.10 as shown) and material utilization (as shown Fig.11 The maximum and minimum stresses are 0.673 kN / m 2 and -0.699kN / m 2 , the maximum material utilization rate is reduced to 99.8%. The weight of the optimized structure is reduced to 11755.2kg, and the material volume is 29.4m 3 The optimization calculation took 14.6 seconds, and the computer configuration used was: CPU-i7-9700, DDR4, RAM 64G.

[0294] 5. Optimization result verification

[0295] In order to ensure that the optimized components meet the structural safety requirements, it is necessary to connect the verification module to perform stability and deformation verification on the optimized components to verify whether they meet the safety constraints.

[0296] First: Anti-overturning calculation

[0297] After completing the structural optimization, the load effect value under the ultimate bearing capacity state was used to calculate and analyze the overall anti-overturning capacity of the structure. The calculation is intended to verify the stability performance of the structure under the specified load. The results obtained through program calculation show that under the wind load of once in 50 years, the anti-overturning safety factor of the structure meets the requirements of relevant specifications, as shown in the program and results of the stability verification. Specifically, the calculated current overturning moment value is lower than the design value of the anti-overturning moment of the structure, which confirms that the stability of the structure meets the specification inspection standards.

[0298] (2) Stability verification

[0299] For the optimized structure, the load effect value under the ultimate bearing capacity state is used to perform finite element calculation on the compression and bending members to verify the stability of the members. The program calculation results show that the stability calculation meets the requirements of less than or equal to the design value of compressive strength of 0.9N / cm 2 The design value of bending strength is 0.99N / cm 2 At the same time, the calculated result of the lateral stability of the compression-bending member outside the moment action plane is less than 1; the maximum slenderness ratio of the bending member is 10.99, which meets the requirement of the specification that it is less than 50.

[0300] (3) Deflection verification

[0301] The deflection of the bending member can be calculated using the load effect value under the normal service limit state. By checking the displacement cloud map, it is found that the maximum displacement of the structure occurs at the purlin position, with a value of 1.94cm. According to the requirements of the specification, for beams and rafters, the deflection should be controlled within 1 / 250 of the span; for purlins with a span of more than 3.3m, the deflection verification standard is also 1 / 250; and for purlins with a span of no more than 3.3m, the deflection should be controlled below 1 / 200. Based on these standards, a deflection verification program was developed in Grasshopper to verify each bending member. The results show that the deflection of all members meets the requirements of the specification.

[0302] 6. Comparison before and after optimization

[0303] By comparing the cross-sectional dimensions, structural weight and material consumption of the components before and after optimization, as shown in Table 7. First of all, due to the important load transfer tasks of the first-floor beam, the first-floor middle column beam, the Leigong column, the Taiping beam, the middle column and the main beam in the structure, as well as the special position of the first-floor body melon column, the hanging column and the eaves column, the cross-sectional dimensions of these nine types of components were optimized by increasing. The optimization results show that the cross-sectional dimensions of the three types of components, namely the first-floor beam, the first-floor body melon column and the hanging column, have been appropriately increased after optimization. The maximum value of the total structural utilization rate has dropped from 104.0% to 99.8%, and the safety of the components has been optimized. At the same time, the cross-sectional dimensions of the remaining eight types of components have been reduced. By reducing the excessive use of materials, the bearing capacity of the structure has been more reasonably distributed, thereby improving the overall stability and durability of the structure. Compared with before optimization, the total weight of the optimized structure has been reduced by 409.1kg to 11755.2kg, and the material consumption has been reduced by 1m 3 , down to 29.4m 3 The structural weight and material usage optimization rate is 3.3%.

[0304] Table 7 Comparison of structural materials before and after optimization

[0305]

[0306]

[0307] In order to solve the reading comprehension difficulties caused by the wide variety of components, this embodiment draws a schematic diagram of the spatial positions of the components of Wu Liuxiong's Drum Tower, so as to help readers more intuitively understand the relative positions between the components and their functions in the overall structure.

[0308] 7. Verification of theoretical size range

[0309] By inputting the size range in Table 8 into the program, new size data are given to various main components of Wu Liuxiong's Drum Tower, and key performance indicators such as internal force, stress, deflection and material utilization rate of the structure under each size set are obtained through iterative calculation. After checking the constraint conditions, the melon column diameter of 210mm can be used as the lower limit of the modular size. If the modular size of the component is lower than the value listed in Table 9, the design scheme will be deemed unsafe.

[0310] Table 8 Relationship between cross-sectional dimensions and modulus of main structural components of Drum Tower

[0311]

[0312]

[0313] Table 9 The lower limit of safety of theoretical modular dimensions under the structural form of Wu Liuxiong's Drum Tower

[0314]

[0315] This embodiment is mainly based on the parametric design optimization platform. By selecting the Wu Liuxiong Drum Tower case in Gaoding Village, Sanjiang County, Guangxi Zhuang Autonomous Region, the method described in Example 1 is applied and verified through the developed platform. The design parameters of the drum tower of the target case are obtained through field investigation. By inputting the design parameters of the drum tower in the Rhino&Grasshopper platform, the key performance indicators such as internal force, stress, deflection and material utilization rate of the drum tower under the load condition are analyzed through the parametric finite element analysis program, and the effectiveness of the parametric finite element analysis program is verified. With the help of the component importance evaluation program, the key components in the structure can be automatically located, and the component importance distribution cloud map can be generated at the same time to realize the visualization of the importance of the structural components. The component size optimization program is connected to optimize the minimum cross-sectional size under the ultimate state of the strength bearing capacity of the component with full stress as the criterion. The load effect values ​​under the ultimate state of bearing capacity and the normal use limit state are used to carry out anti-overturning, stability and deflection verification of the optimized structure and components, and the verification results meet the corresponding constraints. By comparing before and after optimization, it was found that the structural indicators of component stress, deflection and material utilization rate were reduced after optimization, and the volume of structural materials and the weight of the structure were greatly reduced, which verified the effectiveness of the component size optimization method and optimization procedure.

[0316] Example 3

[0317] This embodiment provides a Drum Tower parametric design optimization system based on structural safety, which is used to execute the Drum Tower parametric design optimization method based on structural safety described in Example 1, including:

[0318] A construction module is used to construct a Drum Tower axis model, and import the Drum Tower axis model into the Drum Tower Rhino & Grasshopper parametric platform to obtain a parametric geometric model with adjustable size;

[0319] A key performance indicator acquisition module is used to set analysis parameters on the Gulou Rhino&Grasshopper parametric platform, wherein the analysis parameters include vertical load, wind load, material properties, section size, nodes and constraints, and obtain the key performance indicators of the Gulou under the load condition through the analysis of the Gulou Rhino&Grasshopper parametric platform, wherein the key performance indicators include internal force, stress, deflection and material utilization rate;

[0320] A component importance calculation module is used to automatically locate key components in the structure of the Drum Tower based on the key performance indicators and using a component importance calculation method, and to generate a component importance distribution cloud map to visualize the component importance;

[0321] An optimization module is used to optimize the size of the key component according to the full stress criterion to obtain the minimum cross-sectional size of the optimized component under the ultimate strength bearing capacity state;

[0322] The result visualization module is used to verify the anti-overturning, stability and deflection of the optimized components using the load effect values ​​under the ultimate bearing capacity limit state and the normal use limit state. If the verification results meet the corresponding constraints, it indicates that the structural optimization of the Drum Tower is successful, and the optimization results are visualized.

[0323] In summary, the parametric design optimization method and system of the drum tower based on structural safety provided by the present invention determine the geometric size constraints based on Karamba3D on the Rhino&Grasshopper parametric platform; iteratively calculate the optimal cross-sectional dimensions of columns, beams, purlins and rafters based on the full stress criterion; and perform safety verification on the optimized components to ensure that the optimized components meet the "Wood Structure Design Standards".

[0324] The remaining technical features in this embodiment can be flexibly selected by those skilled in the art according to actual conditions to meet different specific practical needs. However, it is obvious to those skilled in the art that it is not necessary to adopt these specific details to implement the present invention. In other examples, in order to avoid confusing the present invention, the well-known components, structures or parts are not specifically described, which are all within the technical protection scope defined by the technical solution claimed for protection in the claims of the present invention.

[0325] Modifications and changes made by those skilled in the art that do not depart from the spirit and scope of the present invention should be within the scope of protection of the claims attached to the present invention. In the above description, a large number of specific details are set forth in order to provide a thorough understanding of the present invention. However, it is obvious to those of ordinary skill in the art that these specific details are not necessary to practice the present invention. In other examples, in order to avoid confusing the present invention, well-known technologies, such as specific construction details, operating conditions and other technical conditions, are not specifically described.

[0326] The principles and implementation methods of the present invention are described in this article using specific examples. The description of the above embodiments is only used to help understand the method and core idea of ​​the present invention. At the same time, for those skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A parametric design optimization method for a drum tower based on structural safety, characterized in that: The following steps are involved: S1. Construct a three-dimensional axis model of the Drum Tower, and import the three-dimensional axis model into the Rhino&Grasshopper parametric platform to obtain a parametric geometric model with adjustable size; S2. Setting analysis parameters on the Rhino&Grasshopper parametric platform, wherein the analysis parameters include vertical load, wind load, material properties, section size, nodes and constraints, and obtaining key performance indicators of the Drum Tower under load conditions through finite element analysis on the Rhino&Grasshopper parametric platform based on a finite element model, wherein the key performance indicators include internal force, stress, deflection, material utilization, stability and strength; S3. Based on the key performance indicators, a component importance calculation method is used to automatically locate key components in the structure of the Drum Tower, and a component importance distribution cloud map is generated to visualize the component importance; S4. Optimizing the size of the key component according to the full stress criterion to obtain the minimum cross-sectional size of the optimized component under the ultimate load-bearing capacity state; S5. Use the load effect values ​​under the ultimate bearing capacity state and the normal use limit state to verify the anti-overturning, stability and deflection of the optimized components. If the verification results meet the corresponding constraints, it means that the structural optimization of the Drum Tower is successful, and the optimization results are visualized.

2. The parametric design optimization method of the Drum Tower based on structural safety according to claim 1 is characterized in that: In S3, the component importance calculation method is used to evaluate the importance of each component based on the key performance indicators, including component unit redefinition, unit importance calculation and importance ranking visualization; The component unit redefinition is the process of classifying and describing each component in the engineering structure, including redefining the material properties of the component and describing in detail the position, function and stress condition of the component in the drum tower structure; Unit importance calculation is a key link in evaluating the importance of each component. It is used to develop a component importance evaluation method based on energy flow, comprehensively considering the basic properties of the component, the stress condition, and whether it meets engineering experience, and quantitatively calculate the importance of the component; Importance ranking visualization is to display the calculated component importance index in an intuitive way, and to rank and label the importance of the components.

3. The parametric design optimization method of Drum Tower based on structural safety according to claim 1 is characterized in that: S4, optimizing the size of the key component according to the full stress criterion to obtain the minimum cross-sectional size of the optimized component under the ultimate strength bearing capacity state, specifically includes: S401. Set a component size sequence arranged from small to large and input it into the Rhino&Grasshopper parametric platform as a design variable. Under the premise of satisfying the rationality of node connection and following the full stress design principle, use the optimized cross-section operator to perform iterative calculation to determine the minimum applicable cross-sectional size of the component. S402. Check the safety index of the optimized and adjusted components and the overall structure. If the check result shows that the safety requirements are met, the current cross-sectional size is determined to be the optimal solution; otherwise, if it is not met, the range of the cross-sectional size must be readjusted.

4. The parametric design optimization method of the Drum Tower based on structural safety according to claim 3 is characterized in that: In S401, an iterative calculation is performed using an optimized cross-section operator to determine the minimum applicable cross-sectional size of the component, specifically including: S4011. Set the analysis conditions of the optimized cross-section operator: sort the cross-sectional dimensions of the components obtained in S401 to obtain a cross-sectional dimension list as a design variable; take the material utilization rate as the optimization target, obtain the component safety index according to the limit state design constraint conditions, and set the number of iterations; S4012. In the optimized cross-section operator, under the premise of considering various mechanical effects, the cross-sectional dimensions of the components are taken as design variables, and minimizing the volume of materials used is taken as the objective function. A mathematical model for optimizing the dimensions of drum tower components is established to optimize the cross-section and obtain the optimal cross-sectional dimension set that minimizes the use of structural materials.

5. The parametric design optimization method of Drum Tower based on structural safety according to claim 1 is characterized in that: In S5, the anti-overturning calculation specifically includes the following steps: S501. Perform overall structural overturning verification, the formula is: M 抗(永久荷载+0.5活荷载) / M 倾(水平荷载设计值) ≥1.0 (3-4) Assuming that the overturning moment calculation surface is the foundation bottom surface, and the force of the overturning moment calculation is the horizontal earthquake action or the standard value of the horizontal wind load, the overturning moment is: <h2 style=";text-align:left;direction:ltr">M<h2 style=";text-align:left;direction:ltr"> OV <h2 style=";text-align:left;direction:ltr"> =V0(2H / 3+C) (3-5) Where M OV ——Standard value of overturning moment; H——Height of the building above the ground, i.e., building height; C——Deepness of basement; V0——Standard value of total horizontal force; Assuming the anti-overturning moment calculation point is the outer edge point of the foundation, and the anti-overturning moment calculation force is the representative value of the total gravity load, the anti-overturning moment is expressed as: M R GB / 2(3-6) Where M R ——Standard value of anti-overturning moment; G——Representative value of total gravity load of upper part and basement foundation, i.e. standard value of permanent load + 0.5 standard value of live load; B——Width of bottom surface of basement.

6. The parametric design optimization method of Drum Tower based on structural safety according to claim 1 is characterized in that: In S5, the stability verification specifically includes the following steps: S502. In Karamba3D, perform finite element calculation on the load effect value under the ultimate bearing capacity state of the structure, and calculate the stability coefficient φ of the axial compression member and the lateral stability coefficient φ of the bending member in Grasshopper. l and the reduction factor φ considering the combined effect of axial force and initial bending moment m , then φ, φ l ,φ m Substitute the stability constraint formula of the compression-bending member into Grasshopper to determine whether each type of member meets the stability constraint. Use the following formula to determine whether the stability constraint is met: The stability factor of axially compressed members is calculated according to the following formula: When λ>λ c hour: When λ≤λ c hour: Where, λ is the slenderness ratio of the compression member; i is the radius of gyration of the member section, in mm; l0 is the calculated length of the compression member, in mm; f ck ——The standard value of compressive strength of compression member materials is in N / mm 2 ; E k ——Standard value of elastic modulus of component material, in N / mm 2 ; a c , b c 、c c ——Material correlation coefficient; β——Material shear deformation correlation coefficient; The lateral stability factor of the bending member is calculated according to the following formula: When B >λ m hour: When B ≤λ m hour: Where: B ——The slenderness ratio of bending members should not be greater than 50; e ——calculated length of the bending member, in mm; b——section width of the bending member, in mm; h——section height of the bending member, in mm; f mk ——Standard value of bending strength of bending member material, in N / mm 2 ; a m 、b m 、c m ——Material correlation coefficient; The reduction factor considering the combined effect of axial force and initial bending moment is calculated according to the following formula: Where A is the calculated area of ​​the component cross section, in mm 2 .

7. The parametric design optimization method of Drum Tower based on structural safety according to claim 1 is characterized in that: The constraint conditions include the constraint conditions of the bending members and the compression-bending members under the ultimate bearing capacity state and the constraint conditions under the normal use limit state respectively; Under the ultimate bearing capacity state, the design requirements for the structural components of the Dong Drum Tower are as follows: γ0S d ≤R d (3-7) In the formula, γ0 is the structural importance coefficient; S d ——design value of effect of load combination; R d — design value of resistance of structural members; The calculation requirements for the design value of the effect controlled by variable loads are as follows: In the formula, ——Partial coefficient of permanent load, which is 1.2 when the permanent load is unfavorable to the structure and less than 1.0 when it is favorable; ——The partial factor of variable load is 1.4; - Adjustment factor for variable loads taking into account the design service life; ——Load effect value calculated from the standard value of permanent load; ——Load effect value calculated from the standard value of variable load, where: It plays a controlling role in the variable load effects; ——Combination value coefficient of variable load; m, n——number of permanent and variable loads participating in the combination; The restraint conditions for flexural members are as follows: Constraints under the ultimate bending capacity state: In the formula, f m ——Design value of flexural strength of component material, in N / mm 2 ; M——Design value of bending moment of bending member, in N·mm; W n ——Net section resistance moment of bending member, unit: mm 3 ; Strength requirements under the ultimate shear bearing capacity state: Where: f V ——Design values ​​of bending strength and shear strength along the grain of the component material; V——Design value of shear force of bending components; I——Full section moment of inertia of the component; b——Cross-sectional width of the component; S——Area moment of the cross-sectional area above the shear plane about the neutral axis; Stability requirements under the ultimate bearing capacity state: in, ——lateral stability factor of bending members; The constraints of compression-bending members are as follows: Strength requirements under ultimate bearing capacity state: Where, N is the design value of axial pressure; M0 is the design value of the maximum initial bending moment at mid-span under lateral load; A n ——net cross-sectional area of ​​the component section; W n ——Compute the full section resistance moment of the component; e0——The initial eccentricity of the axial pressure of the component, if uncertain, it shall be 0.05 times the section height of the component; f c 、f m ——Design values ​​of tensile strength and flexural strength along the grain of component materials after considering the adjustment coefficient; Stability requirements under the ultimate bearing capacity state: In the formula, ——Stability coefficient of axially compressed members and reduction coefficient considering the combined effect of axial force and initial bending moment; A0——Calculated area of ​​the member cross section.

8. The parametric design optimization method of Drum Tower based on structural safety according to claim 1 is characterized in that: The key components include all wooden component units, beams, columns and rafters of the Drum Tower.

9. A parametric design optimization system for a drum tower based on structural safety, used to execute the parametric design optimization method for a drum tower based on structural safety according to any one of claims 1 to 8, characterized in that: include: A construction module is used to construct a three-dimensional axis model of the Drum Tower, and import the three-dimensional axis model into the Rhino&Grasshopper parametric platform to obtain a parametric geometric model with adjustable size, define component units, and generate a finite element model; A key performance indicator acquisition module is used to set analysis parameters on the Rhino&Grasshopper parametric platform, wherein the analysis parameters include vertical load, wind load, material properties, section size, nodes and constraint conditions, and based on a finite element model, obtain key performance indicators of the Drum Tower under load conditions through finite element analysis on the Rhino&Grasshopper parametric platform, wherein the key performance indicators include internal force, stress, deflection, material utilization, stability and strength; A component importance calculation module is used to automatically locate key components in the structure of the Drum Tower based on the key performance indicators and using a component importance calculation method, and to generate a component importance distribution cloud map to visualize the component importance; An optimization module is used to optimize the size of the key component according to the full stress criterion to obtain the minimum cross-sectional size of the optimized component under the ultimate load capacity state; The result visualization module is used to verify the anti-overturning, stability and deflection of the optimized components using the load effect values ​​under the ultimate bearing capacity limit state and the normal use limit state. If the verification results meet the corresponding constraints, it indicates that the structural optimization of the Drum Tower is successful, and the optimization results are visualized.

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