A fiber model method-based point matching calculation method and system for bearing capacity-related equations of CFST members
Patent Information
- Application Number
- CN202610959976.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-06-30
- Publication Date
- 2026-10-27
AI Technical Summary
[0054]通过材料本构关系修正模型，对钢材的受拉区及受压区进行区分，真实地反映了钢管在双轴应力状态下的受力特性；对混凝土考虑了钢管约束对混凝土强度和延性的提升，使计算结果更接近实际极限状态。通过自适应间距配点筛选方法，从大量数据中筛选出有效代表性配点。在保证计算精度的同时有效减少了配点数量，提高了计算效率。本发明的齐次广义屈服函数满足塑性极限分析的比例加载条件，克服了现有规范中分段非齐次函数的缺陷，更加符合力学原理。
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Abstract
Description
Technical Field
[0001] This invention relates to the field of structural engineering technology, and in particular to a method and system for calculating the collocation of points based on the fiber model method for the bearing capacity related equations of CFST members. Background Technology
[0002] Concrete-steel tubular (CFST) members, leveraging the synergistic effect of the steel tubing and core concrete, exhibit superior mechanical properties such as high load-bearing capacity, good ductility, and convenient construction, making them key load-bearing components in engineering structures such as high-rise buildings and long-span bridges. In the structural design and safety assessment system for CFST members, the compression-bending capacity correlation equation (i.e., the relationship between axial force N and bending moment M) is the core basis, and its accuracy directly determines the economic efficiency of the member design and the safety of the structure.
[0003] Currently, the design of CFST member bending capacity both domestically and internationally largely relies on relevant standards and specifications. However, existing technologies still have significant limitations: First, existing standards often use piecewise non-homogeneous functions to describe the NM correlation, failing to meet the basic conditions for proportional loading in plastic limit analysis, leading to discrepancies between theoretical derivation and engineering application. Second, the confinement coefficient, a key parameter affecting the mechanical properties of CFST members, is not adequately incorporated into existing equations, failing to accurately reflect the changes in bearing capacity under different constraint effects. Third, the slenderness ratio and eccentricity of the member have a significant coupling effect on the NM correlation, and existing methods struggle to quantify this coupling effect simultaneously, resulting in insufficient calculation accuracy under complex conditions. Furthermore, standards generally use the maximum tensile strain of the steel tube (0.01) as the failure criterion, failing to fully consider the strain hardening effect of the steel tube material, leading to conservative calculation results for bending capacity and material waste. Finally, existing technologies lack a systematic method for obtaining NM correlation points, especially failing to clearly distinguish between strength failure and stability failure point allocation strategies, resulting in a lack of scientific basis for constructing correlation curves.
[0004] The fiber model method, as a numerical analysis technique based on the plane section assumption, can accurately and conveniently solve the axial compression, pure bending, and compression-bending bearing capacities of CFST members, providing an effective tool for calculating NM correlations. However, how to efficiently obtain the collocation points of NM correlation curves covering different failure modes using the fiber model method, and establish a homogeneous generalized yield function that satisfies proportional loading conditions and is suitable for engineering design, remains a pressing technical challenge. Summary of the Invention
[0005] To address the aforementioned problems, this invention provides a method and system for calculating the collocation points of CFST members based on the fiber model method, which can efficiently and accurately establish the bearing capacity correlation equations for CFST members. The relevant equations are obtained, and while ensuring calculation accuracy, the number of collocation points is effectively reduced, thus improving calculation efficiency.
[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:
[0007] A method for calculating the collocation points of CFST members based on the fiber model method includes the following steps:
[0008] S1. Construct a fiber model method calculation framework to determine the material constitutive relation correction model, wherein the relation correction model includes a steel tube constitutive relation correction model and a core concrete constitutive relation correction model;
[0009] S2. For the strength bearing capacity related equations, short column specimens are selected, and the frame is calculated using the fiber model method, with the eccentricity varied. , obtain The relevant curves show a series of strength and bearing capacity points;
[0010] S3. For the relevant equations of stable bearing capacity, select long column specimens and calculate the frame using the fiber model method, while simultaneously changing the slenderness ratio. and eccentricity Obtain the corresponding slenderness ratio The stable bearing capacity distribution points of the relevant curves;
[0011] S4. Based on the preset spacing, representative data points are selected from the strength bearing capacity points and the stability bearing capacity points;
[0012] S5. Based on the representative data points, establish the strength homogeneous generalized yield function and the stability homogeneous generalized yield function respectively using regression analysis to obtain the CFST component. Correlation equations.
[0013] Furthermore, in step S1, the corrected constitutive model of the steel pipe includes a tension zone and a compression zone.
[0014] In the tension zone, the steel pipe is under biaxial unidirectional stress with tension in both the longitudinal and circumferential directions. A three-segmented model considering strain hardening is adopted to reflect the stress characteristics of the steel pipe in the tension zone.
[0015] In the compression zone, the steel pipe is subjected to circumferential tension and longitudinal compression, and an ideal elastic-plastic model is adopted to reflect the biaxial reverse adverse stress state.
[0016] The core concrete constitutive relation correction model includes an ascending segment, a peak point, and a descending segment.
[0017] The ascending segment adopts the Hognestad parabolic model;
[0018] The peak stress formula is fitted based on short column test data, and the peak strain is corrected based on the peak strain of plain concrete by the confinement effect of steel pipe.
[0019] The descent segment adopts a linear descent segment form.
[0020] Further, in step S2, the method for obtaining the strength bearing capacity points includes:
[0021] S2.1 Set the geometric and material parameters of the short column specimen;
[0022] S2.2 Change the eccentricity within a preset range ;
[0023] S2.3 For each of the aforementioned eccentricities The ultimate bearing capacity of the frame is calculated using the fiber model method.
[0024] S2.4 Record the axial force under each ultimate bearing capacity. and bending moment In order to obtain the strength bearing capacity points.
[0025] Further, in step S2.1, the geometric parameters include length. , cross-sectional diameter Steel pipe wall thickness The material parameters include the yield strength of steel. Concrete compressive strength Elastic modulus of steel ;
[0026] In step S2.2, the eccentricity e ranges from 16 mm to... The step size is △e, where The value is 200mm, and Δe = 8mm.
[0027] Further, in step S3, the method for obtaining the stable bearing capacity points includes:
[0028] S3.1 Set the geometric and material parameters of the long column specimen;
[0029] S3.2 Change the slenderness ratio within the preset range ;
[0030] S3.3 For each set slenderness ratio The corresponding change in eccentricity ;
[0031] S3.4 Calculate different slenderness ratios using the fiber model method calculation framework. and eccentricity Ultimate bearing capacity under combined conditions;
[0032] S3.5 Record and output the axial force under each ultimate bearing capacity. Bending moment and the corresponding slenderness ratio To obtain the stable bearing capacity points.
[0033] Further, the geometric parameters mentioned in step S3.1 include length. , cross-sectional diameter Steel pipe wall thickness The material parameters include the yield strength of steel. Concrete compressive strength And the elastic modulus of steel ;
[0034] In steps S3.2 and S3.3, the slenderness ratio λ ranges from 12 to 120, covering the commonly used range in engineering, with a step size Δλ = 12; the eccentricity e ranges from 16 mm to... The step size is △e, where The value is 200mm, and Δe = 8mm.
[0035] Further, in step S4, the method for determining the preset spacing includes:
[0036] S4.1 Calculate the axial compressive strength of each of the aforementioned components. and flexural bearing capacity In order to obtain two representative data points;
[0037] S4.2 Selection The point, among which, The axial compressive bearing capacity of the component under the current slenderness ratio and eccentricity. We take values from 0.9 to 0.2 and decrease them by 0.1 in increments to obtain eight representative data points.
[0038] Furthermore, in step S5, the method for establishing the homogeneous generalized yield function includes the following steps:
[0039] S5.1 The axial force The bending moment M is then dimensionless to obtain a dimensionless axial force. dimensionless bending moment ,in For axial compressive strength bearing capacity, For bending bearing capacity;
[0040] S5.2 Based on the dimensionless axial force and the dimensionless bending moment, construct the strength homogeneous generalized yield function and the stability homogeneous generalized yield function:
[0041] The intensity homogeneous generalized yield function is:
[0042] Formula (1)
[0043] Where ξ is the clamping coefficient, These are coefficients to be determined;
[0044] The stable homogeneous generalized yield function is:
[0045] Formula (2)
[0046] Where φ is the stability coefficient; These are coefficients to be determined.
[0047] Furthermore, in step S5.2, the undetermined coefficients are determined by least squares fitting, and the fitting objective is to minimize the sum of squared residuals between the homogeneous generalized yield function and the collocation points calculated by the fiber model method.
[0048] A system for calculating the collocation points of the bearing capacity correlation equations of CFST members based on the fiber model method, to implement the aforementioned method for calculating the collocation points of the bearing capacity correlation equations of CFST members based on the fiber model method, includes:
[0049] The framework building module is used to construct the computational framework for the fiber model method.
[0050] The parameter setting module is used to set the geometric and material parameters of CFST components;
[0051] The point acquisition module is used to acquire the strength bearing capacity points and the stability bearing capacity points based on the fiber model method calculation framework, and to select representative data points from the strength bearing capacity points and the stability bearing capacity points according to a preset spacing.
[0052] The equation construction module is used to establish the homogeneous generalized yield function, and based on the representative data points, to obtain the CFST component. Correlation equations.
[0053] The beneficial effects of this invention are
[0054] By using a material constitutive relation correction model, the tension and compression zones of steel are distinguished, realistically reflecting the stress characteristics of steel pipes under biaxial stress. For concrete, the enhancement of strength and ductility by the steel pipe constraint is considered, making the calculation results closer to the actual limit state. An adaptive spacing point selection method is used to select effective representative points from a large amount of data. This effectively reduces the number of points while maintaining calculation accuracy, improving computational efficiency. The homogeneous generalized yield function of this invention satisfies the proportional loading condition for plastic limit analysis, overcoming the shortcomings of piecewise non-homogeneous functions in existing specifications and better conforming to mechanical principles. Attached Figure Description
[0055] Figure 1 This is a flowchart of a preferred embodiment of the present invention.
[0056] Figure 2 This is a flowchart of obtaining the strength bearing capacity point allocation according to a preferred embodiment of the present invention.
[0057] Figure 3 This is a flowchart of obtaining the stable bearing capacity points according to a preferred embodiment of the present invention.
[0058] Figure 4 This is a flowchart illustrating the acquisition of representative data points according to a preferred embodiment of the present invention.
[0059] Figure 5 This is a comparison chart of the strength HGYF and fiber model method results of a preferred embodiment of the present invention.
[0060] Figure 6 This is a comparison chart of the results of the stable HGYF method and the fiber model method in a preferred embodiment of the present invention.
[0061] Figure 7 This is a graph showing the variation trend of HGYF under different slenderness ratios according to a preferred embodiment of the present invention.
[0062] Figure 8 This is a comparison chart of HGYF results and bias test data results of a preferred embodiment of the present invention.
[0063] Figure 9 This is a diagram illustrating the iterative process of the stability bearing capacity of an arch bridge according to a preferred embodiment of the present invention. Detailed Implementation
[0064] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0065] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.
[0066] Please also see Figures 1 to 9 The preferred embodiment of the present invention provides a method for calculating the collocation points of the bearing capacity related equations of CFST members based on the fiber model method, comprising the following steps:
[0067] S1. Construct a fiber model method calculation framework to determine the material constitutive relation correction model, which includes the steel tube constitutive relation correction model and the core concrete constitutive relation correction model.
[0068] In step S1, the corrected constitutive model of the steel pipe includes the tension zone and the compression zone.
[0069] In the tension zone, the steel pipe is under biaxial unidirectional stress with tension in both the longitudinal and circumferential directions. A three-segmented model considering strain hardening is adopted to reflect the stress characteristics of the steel pipe in the tension zone.
[0070] In the compression zone, the steel pipe is subjected to circumferential tension and longitudinal compression. An ideal elastic-plastic model is adopted to reflect the biaxial reverse adverse stress state.
[0071] The core concrete constitutive relation correction model includes the rising segment, peak point, and falling segment.
[0072] The ascending segment uses the Hognestad parabola model;
[0073] The peak stress formula is fitted based on short column test data, and the peak strain is corrected based on the peak strain of plain concrete through the confinement of steel pipe.
[0074] The descent segment adopts a linear descent segment form.
[0075] S2. For the strength bearing capacity related equations, short column specimens are selected, and the frame is calculated using the fiber model method, with the eccentricity varied. , obtain The relevant curves show a series of strength and bearing capacity points.
[0076] like Figure 2 As shown, in step S2, the method for obtaining the strength bearing capacity points includes:
[0077] S2.1 Set the geometric and material parameters of the short column specimen.
[0078] In step S2.1, the geometric parameters include length. , cross-sectional diameter Steel pipe wall thickness Material parameters include the yield strength of steel. Concrete compressive strength Elastic modulus of steel .
[0079] S2.2 Change the eccentricity within the preset range .
[0080] In step S2.2, the eccentricity e ranges from 16 mm to... The step size is △e, where The value is 200mm, and Δe = 8mm.
[0081] S2.3 For each eccentricity The ultimate bearing capacity of the frame is calculated using the fiber model method.
[0082] S2.4 Record the axial force under each ultimate bearing capacity. and bending moment To obtain the strength and bearing capacity points.
[0083] S3. For the relevant equations of stable bearing capacity, select long column specimens and calculate the frame using the fiber model method, while simultaneously changing the slenderness ratio. and eccentricity Obtain the corresponding slenderness ratio The stable bearing capacity of the relevant curves.
[0084] In step S3, the method for obtaining the stable bearing capacity distribution points includes:
[0085] S3.1 Set the geometric and material parameters of the long column specimen.
[0086] The geometric parameters in step S3.1 include length. , cross-sectional diameter Steel pipe wall thickness Material parameters include the yield strength of steel. Concrete compressive strength And the elastic modulus of steel .
[0087] S3.2 Change the slenderness ratio within the preset range .
[0088] S3.3 For each set slenderness ratio The corresponding change in eccentricity .
[0089] In steps S3.2 and S3.3, the slenderness ratio λ ranges from 12 to 120, covering the commonly used range in engineering, with a step size Δλ = 12; the eccentricity e ranges from 16 mm to... The step size is △e, where The value is 200mm, and Δe = 8mm.
[0090] S3.4 Calculation of different slenderness ratios using the fiber model method and eccentricity Ultimate bearing capacity under combined conditions;
[0091] S3.5 Record and output the axial force under each ultimate bearing capacity. Bending moment and the corresponding slenderness ratio In order to obtain a stable load-bearing capacity distribution point.
[0092] S4. Based on the preset spacing, select representative data points from the strength bearing capacity points and the stability bearing capacity points.
[0093] In step S4, the method for determining the preset spacing includes:
[0094] S4.1 Calculate the axial compressive strength of each component. and flexural bearing capacity In order to obtain two representative data points;
[0095] S4.2 Selection The point, among which, The axial compressive bearing capacity of the component under the current slenderness ratio and eccentricity. We take values from 0.9 to 0.2 and decrease them by 0.1 in increments to obtain eight representative data points.
[0096] S5. Based on the representative data points, establish the strength homogeneous generalized yield function and the stability homogeneous generalized yield function respectively using regression analysis to obtain the CFST component. Correlation equations.
[0097] In step S5, the method for establishing the homogeneous generalized yield function includes the following steps:
[0098] S5.1 Axial force The bending moment M is dimensionless to obtain the dimensionless axial force. dimensionless bending moment ,in For axial compressive strength bearing capacity, For bending bearing capacity;
[0099] S5.2 Construct the strength homogeneous generalized yield function and the stability homogeneous generalized yield function based on dimensionless axial force and dimensionless bending moment:
[0100] The strength homogeneous generalized yield function is:
[0101] Formula (1)
[0102] Where ξ is the clamping coefficient, These are coefficients to be determined;
[0103] The stable homogeneous generalized yield function is:
[0104] Formula (2)
[0105] Where φ is the stability coefficient; These are coefficients to be determined.
[0106] In step S5.2, the undetermined coefficients are determined by least squares fitting, and the fitting objective is to minimize the sum of squared residuals between the homogeneous generalized yield function and the collocation points calculated by the fiber model method. When the highest power... When the sum of squared residuals was 0.504 and the root mean square error was 0.036, it had a very high fitting accuracy.
[0107] like Figure 7 The figure shows the trend of homogeneous generalized yield function (HGYF) under different slenderness ratios. As the value increases from 12 to 120, the dimensionless curves related to the compressive-bending capacity ( The curve gradually contracts inward, demonstrating that the structural bearing capacity of the member decreases significantly with increasing slenderness ratio. The smooth and monotonic trend in this embodiment illustrates that the homogeneous generalized yield function can accurately capture the weakening effect of slenderness ratio on the stability performance of CFST members, which is consistent with the basic principles of structural mechanics.
[0108] This embodiment also discloses a point calculation system for the bearing capacity related equations of CFST members based on the fiber model method, including:
[0109] The framework building module is used to construct the computational framework for the fiber model method.
[0110] The parameter setting module is used to set the geometric and material parameters of CFST components;
[0111] The point acquisition module is used to obtain strength bearing capacity points and stability bearing capacity points based on the fiber model method calculation framework, and to select representative data points from the strength bearing capacity points and stability bearing capacity points according to the preset spacing.
[0112] The equation construction module is used to establish the homogeneous generalized yield function and, based on representative data points, obtains the CFST component. Correlation equations.
[0113] This embodiment uses CFST test data on the load-bearing capacity of compression-bending members to verify the second-order generalized yield function.
[0114] The verification in this implementation includes the analysis and verification of the CFST member's compressive-bending capacity and the analysis and verification of the CFST structure's stability capacity:
[0115] The verification of the CFST member's compressive-bending capacity includes:
[0116] Data collection of eccentric compression tests: Based on the eccentric compression test database, 203 sets of rectangular and 330 sets of circular CFST compression-bending capacity test data were collected. The value range of the hoop coefficient ξ of the specimens is 0.3~4.0.
[0117] Establish the HGYF expression: Establish the homogeneous generalized yield function through collocational regression analysis using the fiber model method.
[0118] Calculate bearing capacity: Substitute the experimentally measured parameters into the homogeneous generalized yield function to calculate the compressive-bending bearing capacity of each specimen.
[0119] Comparative verification: such as Figure 8 As shown, the calculated and experimental values of HGYF are compared and analyzed. The horizontal axis represents the experimental value, the vertical axis represents the calculated value, and the diagonal line represents the ideal fit line. Figure 8 As can be seen, the vast majority of data points are closely distributed on both sides of the diagonal, with no obvious systematic bias, which intuitively confirms the accuracy and reliability of HGYF in predicting the bearing capacity of CFST components over a wide range of parameters (especially in the region with high hoop coefficient).
[0120] The verification results show that the mean ratio of the calculated value to the experimental value of the homogeneous generalized yield function of the rectangle is 0.975, and the coefficient of variation is 0.140; the mean ratio of the calculated value to the experimental value of the homogeneous generalized yield function of the circle is 1.026, and the coefficient of variation is 0.168. The calculation accuracy meets the engineering requirements.
[0121] The structural stability and bearing capacity verification of the CFST arch bridge included:
[0122] Establish an arch structure model. The arch axis is parabolic. span Yataka The arch section uses circular steel-concrete composite tubular steel, with the outer diameter of the steel tubing being [missing information]. = 121mm, wall thickness Material parameters are: steel pipe yield strength. Compressive strength of concrete cube Elastic modulus of steel Elastic modulus of concrete .
[0123] Establish the HGYF expression. Based on the fiber model method and collocational regression analysis, the HGYF expression is obtained: .
[0124] Establish a model based on the reduction of the elastic modulus and solve it iteratively.
[0125] like Figure 5 As shown, this illustrates the different clamping coefficients ( The fit between the strength HGYF curve and the calculation points of the fiber model method is shown. Furthermore, regardless of the variation in the confinement coefficient, the fitted curve accurately passes through the discrete calculation points, demonstrating the high accuracy of the strength yield surface construction.
[0126] like Figure 6 As shown, this illustrates the effect of a fixed clamping coefficient ( and Under different slenderness ratios ( The corresponding stability bearing capacity correlation curve; Figure 6 The dense colored curves show that the established stable HGYF can accurately reflect the weakening effect of slenderness ratio on the bending capacity of the member, and is highly consistent with the calculation results of the fiber model method.
[0127] like Figure 9 As shown, with the increase of the number of iterations (from the 1st to the 3rd-4th), the calculated stable bearing capacity quickly converges and tends to a stable value (about 33kN). The final converged calculated value (HGYF P=1, P=50, P=150, etc.) almost completely coincides with the experimental value represented by the horizontal solid line, which proves that when applying HGYF to complex structures, such as the nonlinear analysis of arch bridges, it is not only highly efficient and requires fewer iterations, but also provides stable calculation results that are not affected by the initial load value and have high calculation accuracy.
[0128] Verification results show that the stability bearing capacity of the CFST arch bridge calculated based on the elastic modulus reduction method using the homogeneous generalized yield function has an error of only 0.03% compared to the experimental value, demonstrating high calculation accuracy and stability.
[0129] This embodiment distinguishes between strength bearing capacity and stability bearing capacity, employing different point selection strategies for each, thus comprehensively and accurately describing the NM correlation of CFST components under different stress states. The adaptive spacing point selection method in this embodiment effectively reduces the number of points while ensuring calculation accuracy, improving computational efficiency. The homogeneous generalized yield function in this embodiment satisfies the proportional loading condition for plastic limit analysis, overcoming the shortcomings of piecewise non-homogeneous functions in existing standards and better conforming to mechanical principles. This embodiment reasonably considers the influence of the hoop coefficient on the equation related to compression-bending bearing capacity; the established calculation formula agrees well with the results calculated by the fiber model method, and the error compared to experimental results is less than 3%, demonstrating higher calculation accuracy.
Claims
1. A method for calculating the collocation points of the bearing capacity related equations of CFST members based on the fiber model method, characterized in that, Includes the following steps: S1. Construct a fiber model method calculation framework to determine the material constitutive relation correction model, wherein the relation correction model includes a steel tube constitutive relation correction model and a core concrete constitutive relation correction model; S2. For the strength bearing capacity related equations, short column specimens are selected, and the frame is calculated using the fiber model method, with the eccentricity varied. , obtain The relevant curves show a series of strength and bearing capacity points; S3. For the relevant equations of stable bearing capacity, select long column specimens and calculate the frame using the fiber model method, while simultaneously changing the slenderness ratio. and eccentricity Obtain the corresponding slenderness ratio The stable bearing capacity distribution points of the relevant curves; S4. Based on the preset spacing, representative data points are selected from the strength bearing capacity points and the stability bearing capacity points; S5. Based on the representative data points, establish the strength homogeneous generalized yield function and the stability homogeneous generalized yield function respectively using regression analysis to obtain the CFST component. Correlation equations.
2. The method for calculating the bearing capacity of CFST members based on the fiber model method according to claim 1, characterized in that: In step S1, the corrected constitutive model of the steel pipe includes a tension zone and a compression zone. In the tension zone, the steel pipe is under biaxial unidirectional stress with tension in both the longitudinal and circumferential directions. A three-segmented model considering strain hardening is adopted to reflect the stress characteristics of the steel pipe in the tension zone. In the compression zone, the steel pipe is subjected to circumferential tension and longitudinal compression, and an ideal elastic-plastic model is adopted to reflect the biaxial reverse adverse stress state. The core concrete constitutive relation correction model includes an ascending segment, a peak point, and a descending segment. The ascending segment adopts the Hognestad parabolic model; The peak stress formula is fitted based on short column test data, and the peak strain is corrected based on the peak strain of plain concrete by the confinement effect of steel pipe. The descent segment adopts a linear descent segment form.
3. The method for calculating the bearing capacity of CFST members based on the fiber model method according to claim 1, characterized in that: In step S2, the method for obtaining the strength bearing capacity points includes: S2.1 Set the geometric and material parameters of the short column specimen; S2.2 Change the eccentricity within a preset range ; S2.3 For each of the aforementioned eccentricities The ultimate bearing capacity of the frame is calculated using the fiber model method. S2.4 Record the axial force under each ultimate bearing capacity. and bending moment In order to obtain the strength bearing capacity points.
4. The method for calculating the bearing capacity correlation equations of CFST members based on the fiber model method according to claim 3, characterized in that: In step S2.1, the geometric parameters include length. , cross-sectional diameter Steel pipe wall thickness The material parameters include the yield strength of steel. Concrete compressive strength Elastic modulus of steel ; In step S2.2, the eccentricity e ranges from 16 mm to... The step size is △e, where The value is 200mm, and Δe = 8mm.
5. The method for calculating the bearing capacity correlation equations of CFST members based on the fiber model method according to claim 1, characterized in that: In step S3, the method for obtaining the stable bearing capacity points includes: S3.1 Set the geometric and material parameters of the long column specimen; S3.2 Change the slenderness ratio within the preset range ; S3.3 For each set slenderness ratio The corresponding change in eccentricity ; S3.4 Calculate different slenderness ratios using the fiber model method calculation framework. and eccentricity Ultimate bearing capacity under combined conditions; S3.5 Record and output the axial force under each ultimate bearing capacity. Bending moment and the corresponding slenderness ratio To obtain the stable bearing capacity points.
6. The method for calculating the bearing capacity of CFST members based on the fiber model method according to claim 5, characterized in that: The geometric parameters mentioned in step S3.1 include length. , cross-sectional diameter Steel pipe wall thickness The material parameters include the yield strength of steel. Concrete compressive strength And the elastic modulus of steel ; In steps S3.2 and S3.3, the slenderness ratio λ ranges from 12 to 120, covering the commonly used range in engineering, with a step size Δλ = 12; the eccentricity e ranges from 16 mm to... The step size is △e, where The value is 200mm, and Δe = 8mm.
7. The method for calculating the collocation points of the bearing capacity correlation equation of CFST members based on the fiber model method according to claim 1, characterized in that: In step S4, the method for determining the preset spacing includes: S4.1 Calculate the axial compressive strength of each of the aforementioned components. and flexural bearing capacity In order to obtain two representative data points; S4.2 Selection The point, among which, The axial compressive bearing capacity of the component under the current slenderness ratio and eccentricity. We take values from 0.9 to 0.2 and decrease them by 0.1 in increments to obtain eight representative data points.
8. The method for calculating the collocation points of the bearing capacity related equations of CFST members based on the fiber model method according to claim 1, characterized in that: In step S5, the method for establishing the homogeneous generalized yield function includes the following steps: S5.1 The axial force The bending moment M is then dimensionless to obtain a dimensionless axial force. dimensionless bending moment ,in For axial compressive strength bearing capacity, For bending bearing capacity; S5.2 Based on the dimensionless axial force and the dimensionless bending moment, construct the strength homogeneous generalized yield function and the stability homogeneous generalized yield function: The intensity homogeneous generalized yield function is: Official (1) Where ξ is the clamping coefficient, These are coefficients to be determined; The stable homogeneous generalized yield function is: Official (2) Where φ is the stability coefficient; These are coefficients to be determined.
9. The method for calculating the bearing capacity correlation equations of CFST members based on the fiber model method according to claim 8, characterized in that: In step S5.2, the undetermined coefficients are determined by least squares fitting, and the fitting objective is to minimize the sum of squared residuals between the homogeneous generalized yield function and the collocation points calculated by the fiber model method.
10. A system for calculating the collocation of points based on the fiber model method for the bearing capacity correlation equation of CFST members, to realize the method for calculating the collocation of points based on the fiber model method for the bearing capacity correlation equation of CFST members as described in any one of claims 1-9, characterized in that, include: The framework building module is used to construct the computational framework for the fiber model method. The parameter setting module is used to set the geometric and material parameters of CFST components; The point acquisition module is used to acquire the strength bearing capacity points and the stability bearing capacity points based on the fiber model method calculation framework, and to select representative data points from the strength bearing capacity points and the stability bearing capacity points according to a preset spacing. The equation construction module is used to establish the homogeneous generalized yield function, and based on the representative data points, to obtain the CFST component. Correlation equations.