Simplified simulation and design method for supporting beam column type wood structure

Abstract

The invention discloses a simplified simulation and design method for a supporting beam column type wood structure, relates to the field of building structure simulation design, and provides a numerical simulation scheme for improving calculation efficiency based on openesses through two numerical simulation methods, namely a refined finite element model based on abaqus and simplified numerical simulation based on openesses. Systematic parameterization analysis is carried out on the anti-seismic performance of the semi-rigid connection beam column type laminated wood frame, and factors such as vertical load changes, different beam heights, different supporting forms and different beam column line rigidity ratios are considered, so that the anti-seismic performance of the semi-rigid connection beam column type laminated wood frame is systematically analyzed.

Description

Technical Field

[0001] This invention relates to the field of architectural structure simulation design, specifically to a simplified simulation and design method for timber structures with supported beams and columns. Background Technology

[0002] Beam-column glued laminated timber structures are widely used in modern buildings due to their advantages such as high strength, large span, low carbon emissions, and environmental friendliness. Their seismic performance depends on the matching of the semi-rigid characteristics of the joints with the lateral force resisting system. To address this, two issues need to be resolved: first, how to determine the degree of semi-rigidity of the connection; and second, how to simulate its semi-rigidity in calculations.

[0003] Currently, research on the seismic performance of semi-rigidly connected beam-column glued laminated timber structures mainly relies on experimental methods to obtain the bending and rotation curves of the connections. However, this approach is costly, time-consuming, and unsuitable for practical engineering design. Using the finite element method (FEM) to establish a solid model of the connections provides a supplement to experimental methods, applicable to connections of any size and allowing for the application of combined forces. However, accurately simulating the impact of node stiffness on the overall seismic performance requires establishing a large number of solid elements. Complex contact relationships and a large number of components can lead to excessive computational costs or even non-convergence. Furthermore, modifying the overall model is difficult, making it challenging to design timber structures for different seismic fortification intensities. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention aims to provide a simplified simulation and design method for supported beam-column timber structures. It employs two numerical simulation methods: a refined finite element model based on Abaqus and a simplified numerical simulation based on OpenSees. A numerical simulation scheme based on OpenSees, with improved computational efficiency, is proposed to systematically and parametrically analyze the seismic performance of semi-rigidly connected beam-column glued laminated timber frames. This analysis considers factors such as variations in vertical loads, different beam heights, different support forms, and different beam-column stiffness ratios, thereby systematically analyzing the seismic performance of semi-rigidly connected beam-column glued laminated timber frames.

[0005] This invention is achieved through the following technical solution:

[0006] A simplified simulation and design method for timber structures with supported beams and columns includes the following steps:

[0007] S1: Based on Abaqus, a refined numerical model of the beam-column joints and column base joints of the glued laminated timber structure is established, and low-cycle repeated loads are applied to obtain the moment-rotation curves of the joints in order to quantify their semi-rigid characteristics and extract key feature parameters.

[0008] S2: Based on OpenSees, establish a rod system analysis model for beam-column joints and column base joints of glued laminated timber structures;

[0009] S3: Assign the extracted key feature parameters to the DowelType constitutive model of OpenSees, and assign zero-length elements to the beam-column and column base nodes in the rod system analysis model;

[0010] S4: Subsequently, the same low-cycle repeated load was applied to the OpenSees node-bar system analysis model to perform hysteretic analysis of the glued laminated timber structure nodes, extract the moment-rotation hysteretic curves, and compare them with the moment-rotation curves of the refined numerical model to verify whether the error requirements are met.

[0011] S5: When the error requirements are met, the design parameters of the glued laminated timber structure are initially determined, and the equivalent rotational stiffness of the beam-column joints after the supports are set is theoretically calculated.

[0012] S6: Update the DowelType constitutive model of the beam-column joint based on the equivalent rotational stiffness, and apply the updated model to the rod system analysis model. Extract the structural response under seismic loading through time history analysis.

[0013] S7: Finally, analyze whether it meets the structural seismic requirements. If it does, determine the structural type; if it does not, return to step S5 to determine the various design parameters of the glued laminated timber structure.

[0014] Further optimization, in step S1, the step of extracting key feature parameters includes:

[0015] The envelope of the moment-rotation curve at each node is divided into several straight line segments. The rotation angle Di and bending moment Fi at each point are recorded, as well as the pinch intercept F. I The parameters are: pinch stiffness Kp, unloading stiffness to initial stiffness ratio Ru, Bessel shape factor c, reload displacement amplification factor beta, reload degradation factor gamma due to energy consumption, pinch intercept shift parameter eta, yield displacement Dy, pinch stiffness degradation factor alpha_p, unloading stiffness degradation factor alpha_u, and reload stiffness degradation factor alpha_r.

[0016] For further optimization, the beams and columns in the rod system analysis model are made of elastic beam-column elements or fiber elements that consider material nonlinearity, and the nodes are made of zero-length elements.

[0017] For further optimization, in step S4, when determining whether the error requirement is met, the parameters to be compared include the initial rotational stiffness, the ultimate bending moment, and the yield angle.

[0018] For further optimization, in step S4, when determining whether the error requirement is met, the error must be less than or equal to 15%.

[0019] For further optimization, in step S4, if the error verification requirements are not met, the number of segments in the DowelType constitutive model needs to be adjusted, and the key feature parameters need to be updated. Then, the calculation and verification are resubmitted until the error requirements are met.

[0020] In a further optimization, step S5, the calculation steps for the equivalent rotational stiffness of the beam-column joint include:

[0021] The rotational stiffness K of the beam-column joint is obtained through the refined numerical model. j ;

[0022] The linear stiffness K of the supporting member is then calculated. b And calculate the slip stiffness K of each shear plane for each fastener. c ;

[0023] Calculate the axial stiffness K of the support-bolted connection based on linear stiffness and slip stiffness. s,line The axial stiffness is converted into the supporting rotational stiffness K of the beam-column joint. s,rot ;

[0024] Finally, the rotational stiffness K of the beam-column joint is... j With support rotational stiffness K s,rot By connecting them in parallel, the equivalent rotational stiffness of the beam-column joint considering the supporting effect can be obtained.

[0025] Further optimization involves increasing the linear stiffness K of the supporting member. b The calculation formula is:

[0026] ;

[0027] In the formula, E is the elastic modulus of the support, A is the cross-sectional area, and L is the support length;

[0028] Slip stiffness K of each fastener per shear plane c The calculation formula is:

[0029] ;

[0030] In the formula, u1 and μ2 are regression coefficients, which are taken as 1.5 and 23 respectively according to European standards.

[0031] Further optimization, the axial stiffness K s,line The calculation formula is:

[0032] ;

[0033] Support rotational stiffness K s,rot The calculation formula is:

[0034] ;

[0035] In the formula, h is the vertical distance from the node rotation center to the connection point between the support and the column, and b is the horizontal distance from the node rotation center to the connection point between the support and the beam;

[0036] The formula for calculating the equivalent rotational stiffness of a beam-column joint is:

[0037] .

[0038] In a further optimization, in step S6, when updating the DowelType constitutive model of the beam-column node based on the equivalent rotational stiffness, only the moment-rotation characteristics of the node under monotonic loading are updated, ignoring the difference in hysteretic performance caused by the asymmetry of force transmission path and damage accumulation.

[0039] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0040] 1. This invention provides a simplified simulation and design method for timber structures with supported beams and columns. By simulating the support effect at the node level, the support unit is omitted in the overall model, which greatly simplifies the modeling work and improves the calculation efficiency. It is particularly suitable for large-scale parameter analysis and design optimization.

[0041] 2. This invention provides a simplified simulation and design method for supported beam-column timber structures. It uses DowelType elements that can consider positive and negative asymmetry characteristics, which more realistically reflects the actual working state of nodes in supported structures and ensures the accuracy of overall structural response prediction.

[0042] 3. This invention provides a simplified simulation and design method for supported beam-column timber structures, establishing a complete process from joint testing to overall evaluation. It can clearly define the applicable limits of different beam-column joint systems under different fortification intensities and building forms, providing a direct basis for engineering design. Attached Figure Description

[0043] To more clearly illustrate the technical solutions of the exemplary embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly described below. It should be understood that the following drawings only show some embodiments of the present invention and should not be considered as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort. In the drawings:

[0044] Figure 1 A simplified simulation and design flowchart of a timber structure with supporting beams and columns provided by this invention;

[0045] Figure 2 The constitutive model diagram of DowelType provided by this invention;

[0046] Figure 3 The analysis model diagram (left) and the rod system model diagram (right) in the refined numerical model provided for this invention;

[0047] Figure 4 The theoretical analysis model diagram of the beam-column-support node provided by this invention;

[0048] Figure 5 The diagram shows the analysis model of the timber frame system provided by this invention. Detailed Implementation

[0049] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the embodiments and accompanying drawings. The illustrative embodiments and descriptions of the present invention are only used to explain the present invention and are not intended to limit the present invention.

[0050] Example:

[0051] This embodiment provides a simplified simulation and design method for timber structures with supported beams and columns, such as... Figures 1-5 As shown, the specific steps include the following:

[0052] Step 1: Based on the actual project, establish a refined numerical model of the beam-column and column base connection nodes of the timber structure using Abaqus, apply low-cycle repeated loads, obtain the moment-rotation relationship of the nodes, quantify their semi-rigid characteristics, and extract key feature parameters.

[0053] The parameter extraction method is as follows: divide the envelope of the moment-rotation curve of the node into several straight line segments, record the rotation angle Di and bending moment Fi at each point; record the pinch intercept F. I The parameters are: pinch stiffness Kp, unloading stiffness to initial stiffness ratio Ru, Bessel shape factor c, reload displacement amplification factor beta, reload degradation factor gamma due to energy consumption, pinch intercept shift parameter eta, yield displacement Dy, pinch stiffness degradation factor alpha_p, unloading stiffness degradation factor alpha_u, and reload stiffness degradation factor alpha_r.

[0054] Step 2: Establish a truss analysis model for the beam-column and column base nodes of the glued laminated timber structure based on OpenSees. Beams and columns use elastic beam-column elements or fiber elements considering material nonlinearity; nodes use zero-length elements. The member lengths of the beams and columns are consistent with the refined analysis model established in Abaqus. Taking a beam-column node as an example... Figure 3As shown in the right figure, (1) is a wooden column element, (2) is a wooden beam element, and (3) is a node connection. Element (1) is divided into two segments, with three node numbers: 1, 2, and 3. The distance between nodes 1 and 3 is equal to the column length in the refined analysis model. The distance between nodes 2 and 3 is equal to the distance between the beam centerline and the right end of the column in the refined analysis model. The distance between nodes 4 and 5 is equal to the beam length in the refined analysis model. The coordinates of nodes 2 and 4 are completely consistent, forming a zero-length element (3) (the distance between nodes 2 and 4 in the figure is exaggerated to clearly represent the structural features).

[0055] Step 3: Assign the key feature parameters extracted from the 3D numerical model to the DowelType constitutive model in Opensees. The command flow is as follows: uniaxialMaterial DowelType $matTag $F I $Kp $Ru $c $beta $gamma $eta $Dy $alpha_p $alpha_u $alpha_r -piecewise $D1 $F1 $D2 $F2 $D3 $F3<$D4 $F4 ...>; where matTag is the material number; assign the DowelType constitutive model to the beams, columns, and column bases of the rod system model as zero-length elements, with the following command flow: element zeroLength eleTag iNode jNode -mat matTag1matTag2 ... -dir dir1 dir2..., where eleTag is the element number, iNode and jNode are the node numbers at both ends of the element, matTag1 is the material number of the constitutive model, and dir1 and dir2 are the directions to be applied to the material model.

[0056] Step 4: Using OpenSees and a displacement-controlled low-cycle repeated loading regime identical to the refined Abaqus model, perform hysteresis analysis on the glued laminated timber (GLTL) structure nodes. Extract the moment-rotation hysteresis curves and compare them with the refined model results for verification. The comparison parameters mainly include initial rotational stiffness, ultimate bending moment, and yield rotation angle, ensuring the error is less than or equal to 15%. If the verification requirements are not met, adjust the number of segments in the DowelType constitutive model, update the envelope parameters such as Di and Fi, resubmit the calculation and verification until the error requirements are met.

[0057] Step 5: Initially determine the support materials, dimensions, etc., and theoretically calculate the equivalent rotational stiffness of the beam-column joint after the support is set. The theoretical calculation model is as follows: Figure 4 As shown.

[0058] Where K jThe rotational stiffness of the beam-column joint is obtained through the results of a three-dimensional refined analysis model;

[0059] K b To determine the linear stiffness of the support member, since the support primarily resists its own axial deformation, the linear stiffness of the support member is considered elastic, and its calculation formula is as follows:

[0060] ;

[0061] In the formula, E is the support elastic modulus, A is the cross-sectional area, and L is the support length.

[0062] K c To support the slip stiffness of bolted connections to beams and columns, the number of fasteners is related to the shear type, and the calculation formula for each shear plane of each fastener is as follows:

[0063] ;

[0064] In the formula, u1 and μ2 are regression coefficients, which are taken as 1.5 and 23 respectively according to European standards.

[0065] The axial stiffness K of the support-bolted connection can then be calculated. s,line for:

[0066] ;

[0067] Based on the relationship between the nodal force-moment and linear displacement-rotation angle, the axial stiffness K can be determined. s,line Transformed into rotational stiffness K of the beam-column joint s,rot :

[0068] ;

[0069] In the formula, the vertical distance from the node rotation center to the connection point between the support and the column is h, and the horizontal distance to the connection point between the support and the beam is b (i.e., the lever arm from the point of action at both ends of the support to the node center).

[0070] The rotational stiffness K of the beam-column joint j With support rotational stiffness K s,rot Parallel connection yields the equivalent rotational stiffness of the beam-column joint considering the supporting effect:

[0071] .

[0072] Step 6: Update the DowelType constitutive model of the beam-column joint based on the equivalent rotational stiffness. Reassign the updated model to the joints and apply it to the Opensees frame model of the frame structure. Extract the structural response under seismic loading through time history analysis. It should be noted that in this embodiment, when updating the DowelType constitutive model, only the moment-rotation characteristics of the monotonic loading of the joints are updated. Figure 2 The 1→4 path ignores the difference in hysteresis performance caused by the asymmetry between the force transmission path and damage accumulation.

[0073] Finally, analyze whether the timber frame structure meets the seismic requirements. If it does, determine the structural type and complete the structural design. If not, the support system needs to be redesigned, such as modifying parameters like the number of bolts connecting the supports to the beams and columns, the shear method, the support length, the support angle, and the support material. The calculations must then be resubmitted until the requirements are met.

[0074] To address the efficiency issues in numerical simulation in existing technologies, the above scheme employs two numerical simulation methods: a refined finite element model based on Abaqus and a simplified numerical simulation method based on OpenSees. A numerical simulation scheme based on OpenSees to improve computational efficiency is proposed to systematically parametrically analyze the seismic performance of semi-rigid beam-column glued laminated timber frames. This analysis considers factors such as variations in vertical loads, different beam heights, different support forms, and different beam-column stiffness ratios, thereby systematically analyzing the seismic performance of semi-rigid beam-column glued laminated timber frames.

[0075] Those skilled in the art will understand that all or part of the steps in the above facts and methods can be implemented by a program instructing related hardware. The program or the program described therein can be stored in a computer-readable storage medium. When the program is executed, it includes the following steps: at this time, the corresponding method steps are introduced. The storage medium can be ROM / RAM, magnetic disk, optical disk, etc.

[0076] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A simplified simulation and design method for timber structures with supported beams and columns, characterized in that, Includes the following steps: S1: Based on Abaqus, a refined numerical model of the beam-column joints and column base joints of the glued laminated timber structure is established, and low-cycle repeated loads are applied to obtain the moment-rotation curves of the joints in order to quantify their semi-rigid characteristics and extract key feature parameters. S2: Based on OpenSees, establish a rod system analysis model for beam-column joints and column base joints of glued laminated timber structures; S3: Assign the extracted key feature parameters to the DowelType constitutive model of OpenSees, and assign zero-length elements to the beam-column and column base nodes in the rod system analysis model; S4: Subsequently, the same low-cycle repeated load was applied to the OpenSees node-bar system analysis model to perform hysteretic analysis of the glued laminated timber structure nodes, extract the moment-rotation hysteretic curves, and compare them with the moment-rotation curves of the refined numerical model to verify whether the error requirements are met. S5: When the error requirements are met, the design parameters of the glued laminated timber structure are initially determined, and the equivalent rotational stiffness of the beam-column joints after the supports are set is theoretically calculated. S6: Update the DowelType constitutive model of the beam-column joint based on the equivalent rotational stiffness, and apply the updated model to the rod system analysis model. Extract the structural response under seismic loading through time history analysis. S7: Finally, analyze whether it meets the structural seismic requirements. If it does, determine the structural type; if it does not, return to step S5 to determine the various design parameters of the glued laminated timber structure.

2. The simplified simulation and design method for a timber structure with supported beams and columns according to claim 1, characterized in that, In step S1, the step of extracting key feature parameters includes: The envelope of the moment-rotation curve at each node is divided into several straight line segments. The rotation angle Di and bending moment Fi at each point are recorded, as well as the pinch intercept F. I The parameters are: pinch stiffness Kp, unloading stiffness to initial stiffness ratio Ru, Bessel shape factor c, reload displacement amplification factor beta, reload degradation factor gamma due to energy consumption, pinch intercept shift parameter eta, yield displacement Dy, pinch stiffness degradation factor alpha_p, unloading stiffness degradation factor alpha_u, and reload stiffness degradation factor alpha_r.

3. The simplified simulation and design method for a timber structure with supported beams and columns according to claim 1, characterized in that, The beams and columns in the rod system analysis model are made of elastic beam-column elements or fiber elements that consider material nonlinearity, and the nodes are made of zero-length elements.

4. The simplified simulation and design method for a timber structure with supported beams and columns according to claim 1, characterized in that, In step S4, when determining whether the error requirement is met, the parameters to be compared include the initial rotational stiffness, the ultimate bending moment, and the yield angle.

5. The simplified simulation and design method for a timber structure with supporting beams and columns according to claim 4, characterized in that, In step S4, when determining whether the error requirement is met, the error must be less than or equal to 15%.

6. The simplified simulation and design method for a timber structure with supported beams and columns according to claim 1, characterized in that, In step S4, if the error verification requirements are not met, the number of segments in the DowelType constitutive model needs to be adjusted, and the key feature parameters need to be updated. Then, the calculation and verification are resubmitted until the error requirements are met.

7. The simplified simulation and design method for a timber structure with supported beams and columns according to claim 1, characterized in that, In step S5, the calculation steps for the equivalent rotational stiffness of the beam-column joint include: The rotational stiffness K of the beam-column joint is obtained through the refined numerical model. j ; The linear stiffness K of the supporting member is then calculated. b And calculate the slip stiffness K of each shear plane for each fastener. c ; Calculate the axial stiffness K of the support-bolted connection based on linear stiffness and slip stiffness. s,line The axial stiffness is converted into the supporting rotational stiffness K of the beam-column joint. s,rot ; Finally, the rotational stiffness K of the beam-column joint is... j With support rotational stiffness K s,rot By connecting them in parallel, the equivalent rotational stiffness of the beam-column joint considering the supporting effect can be obtained.

8. The simplified simulation and design method for a timber structure with supporting beams and columns according to claim 7, characterized in that, The linear stiffness K of the supporting member b The calculation formula is: ； In the formula, E is the elastic modulus of the support, A is the cross-sectional area, and L is the support length; Slip stiffness K of each fastener per shear plane c The calculation formula is: ； In the formula, u1 and μ2 are regression coefficients, which are taken as 1.5 and 23 respectively according to European standards.

9. A simplified simulation and design method for a timber structure with supporting beams and columns according to claim 7, characterized in that, The axial stiffness K s,line The calculation formula is: ； Support rotational stiffness K s,rot The calculation formula is: ； In the formula, h is the vertical distance from the node rotation center to the connection point between the support and the column, and b is the horizontal distance from the node rotation center to the connection point between the support and the beam; The formula for calculating the equivalent rotational stiffness of a beam-column joint is: 。 10. The simplified simulation and design method for a timber structure with supported beams and columns according to claim 1, characterized in that, In step S6, when updating the DowelType constitutive model of the beam-column joint based on the equivalent rotational stiffness, only the moment-rotation characteristics of the monotonic loading of the joint are updated, ignoring the difference in hysteretic performance caused by the asymmetry of force transmission path and damage accumulation.

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