A self-adaptive method for solving stress concentration factor of concrete-filled steel tubular truss composite beam

Abstract

The application discloses a self-adaptive solving method for stress concentration coefficients of a steel pipe concrete truss type composite beam and belongs to the technical field of stress characteristics of a steel-concrete composite structure bearing member section. The steel pipe concrete truss type composite beam is a flexural bearing member formed by a steel pipe and core concrete to form a combined section and chord bars and web bars to form a truss beam body; the method acquires chord pipe, branch pipe, web bar combined section and material composition information of the bearing beam body, divides the beam body section along chord pipe sections, branch pipe sections, rod piece intersection zones and local strengthening zones, determines the reference stress concentration coefficients of each section according to a preset component coefficient table, and combines wall thickness ratios, diameter-thickness ratios, node included angles, local strengthening and historical checking results to correct section weights, takes combined section composition, beam body zoning and component applicable grade judgment as cores, and gives stress concentration coefficients of the bearing beam body, section applicable grade and composite beam structure adaptation prompts.

Description

Technical Field

[0001] This invention belongs to the technical field of determining the cross-sectional stress characteristics of steel-concrete composite structural load-bearing members (steel-concrete composite truss beams), specifically involving an adaptive solution method for the stress concentration coefficient of steel-concrete composite truss beams. The steel-concrete composite truss beam is a bending load-bearing member consisting of a composite cross-section formed by steel tubes and core concrete, and chords and web members forming a truss beam body. Background Technology

[0002] Steel-concrete composite truss beams are flexural load-bearing members consisting of a composite section formed by steel tubing and core concrete, with chords and web members forming the truss beam structure. They combine the tensile strength of the steel tubing with the compressive strength of the core concrete, exhibiting high flexural stiffness and load-bearing capacity. However, significant geometric and stiffness abrupt changes occur at the core area of ​​nodes where chords and branches intersect, at member intersections, weld transition zones, and at the edges of connecting plates, easily leading to localized stress concentrations. Determining the appropriate stress concentration factor for this type of load-bearing beam is crucial for cross-sectional load-bearing verification, localized reinforcement arrangements, and assessment of the member's load-bearing safety.

[0003] Existing methods for determining stress concentration factors often rely on fixed structural experience or single parameter values, making it difficult to consider the combined effects of steel pipe diameter, wall thickness, node angle, connecting plate thickness, weld size, stiffening rib arrangement, and core concrete filling state on the composite section. When the cross-sectional form or local reinforcement method of the load-bearing beam changes, directly applying a single factor can easily lead to deviations in determining the stress on the section.

[0004] Therefore, an adaptive solution method corresponding to the load-bearing beam of the steel-concrete composite truss beam is needed. This method combines the geometry of the composite section, the intersection of truss members, local reinforcement, and historical verification results to determine and adaptively correct the stress concentration coefficients of different sections of the load-bearing beam, thereby obtaining stress concentration coefficients that better match the cross-sectional characteristics of the target load-bearing member. Summary of the Invention

[0005] The purpose of this invention is to provide an adaptive solution method for the stress concentration factor of a steel-concrete composite truss beam. This method determines the stress concentration factor based on the combined cross-sectional dimensions of the load-bearing beam, the intersection of truss members, and the form of local reinforcement, and then adaptively corrects it based on differences in cross-sectional structure and historical verification results.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0007] An adaptive solution method for stress concentration factors in steel-concrete composite truss beams includes the following specific steps: Step 1: Obtain the composite section parameters of the load-bearing beam; Step 2: Divide the composite beam into sections; Step 3: Determine the reference stress concentration factor; Step 4: Perform adaptive correction based on local section differences; Step 5: Output the stress concentration factor, section applicability level, and structural adaptation hints. With verification records available, the component coefficient table and section weights can be updated using historical records of similar load-bearing beams.

[0008] During the parameter acquisition phase, the combined section parameters of the load-bearing beam include the outer diameter of the steel pipe, wall thickness, member section dimensions, member intersection angle, node location, span section, connecting plate thickness, weld size, bolt arrangement, stiffening rib setting, core concrete filling height, and local transition fillets. These parameters are recorded according to component type and beam section location for subsequent section division and coefficient correction.

[0009] When recording parameters, each component parameter corresponds to the member element, section number, and structural type of the load-bearing beam. Member elements include chords, branches, web members, connecting plates, welds, stiffening ribs, and core-filled concrete; structural types include direct intersection, connecting plate transition, local stiffening, and core-filled reinforcement.

[0010] During the segmentation stage, beam segments are divided according to the continuity of cross-sectional bearing capacity and the location of abrupt changes in cross-section. The node core area is used to characterize the local concentrated effects at the intersection of members; the weld transition area is used to characterize the local changes in the weld toe and the boundary of the deposited metal; the connecting plate area is used to characterize the effects of plate constraints and bolt arrangement; and the local reinforcement area is used to characterize the adjustment of cross-sectional stiffness caused by stiffening ribs and core concrete filling.

[0011] For adjacent beam segments, a transition correction term is set. This term is determined based on segment length, changes in cross-sectional stiffness, wall thickness variation rate, and local fillet radius, and is used to avoid abrupt changes in coefficients between different segments. When multiple local structures are superimposed, weights are determined separately for the primary and secondary structures.

[0012] During the baseline coefficient determination stage, the baseline stress concentration factor is determined by the component coefficient table. The component coefficient table is categorized according to the steel pipe diameter-to-thickness ratio, the wall thickness ratio of branch pipes to chord pipes, the combined section form, the included angle of the nodes, the thickness grade of the connecting plates, the weld size grade, and the stiffening rib arrangement grade. It can be established from standard structural samples or historical verification results of similar load-bearing beams. Once the section parameters of the target load-bearing beam fall into the corresponding grade, the corresponding baseline coefficient is obtained.

[0013] When the parameters of the target load-bearing beam are between two levels, transition values ​​are taken based on the parameter position; when the target beam has multiple influencing factors such as connecting plates, welds and stiffening ribs, the reference coefficient of the core area of ​​the node is determined first, and then local reinforcement and transition section correction are superimposed.

[0014] Historical verification results can be used as the basis for adjusting the benchmark coefficient. These results include structural verification records, load-bearing capacity verification records, strain verification records, or operational verification records for similar composite beam load-bearing structures. These results are only used to correct structural weights and do not change the basic structural classification of the target load-bearing beam.

[0015] The adaptive correction stage focuses on the weighting of beam segments. Segment weights include cross-sectional geometric weights, connection structural weights, local reinforcement weights, and core infill weights. Cross-sectional geometric weights reflect the wall-to-thickness ratio, diameter-to-thickness ratio, and node angles; connection structural weights reflect the thickness of connecting plates, bolt spacing, and weld dimensions; local reinforcement weights reflect the height, spacing, and transition fillet radius of stiffeners; and core infill weights reflect the core concrete infill height and infill continuity.

[0016] When the thickness of the connecting plate of the target load-bearing beam increases, the weld transition is smooth, the stiffening ribs are arranged reasonably, or the core concrete filling is continuous, the correction item for the corresponding section can be adjusted in the direction of reducing stress concentration; when there is a sudden change in local section stiffness of the target beam, insufficient weld size, excessive stiffening rib spacing, or excessively close connecting plate edges, the correction item for the corresponding section should be adjusted in the direction of increasing stress concentration.

[0017] During the results output stage, the applicable grade of the cross-section is determined based on whether the cross-sectional parameters of the load-bearing beam are within the applicable range, whether the beam section is complete, whether the correction items have historical verification basis, and whether there are over-limit structures in the key sections. If the applicable grade is lower than the preset requirements, prompts are given to add transition fillets, adjust the thickness of the connecting plates, optimize the stiffening rib spacing, or supplement the load-bearing verification.

[0018] Compared with the prior art, the present invention has the following effects:

[0019] 1. Solver adaptability for structural components

[0020] Enhanced correlation of load-bearing components: This method takes the load-bearing beam and composite section of the steel-concrete composite truss as the main line, and includes the chord section, branch section, node core area, member intersection area and local reinforcement area into the zoning determination range respectively, which can reflect the influence of different section sections of the load-bearing beam on the stress concentration factor.

[0021] The classification attributes are clear: This invention takes the steel-concrete composite truss beam as a bending load-bearing member, and focuses on the composite section of steel tube and core concrete, the division of truss beam sections composed of chords and web members, local reinforcement and correction, and the determination of the applicable grade of the load-bearing beam section. The stress concentration factor determined is a section stress characteristic index of this load-bearing member, which belongs to the technology of determining the section stress characteristics and structural adaptation of the steel-concrete composite load-bearing member body.

[0022] 2. The correction process is traceable.

[0023] The adaptive correction mechanism is clearly defined: for different wall thickness ratios, node angles, connecting plate thicknesses, weld dimensions, stiffening rib arrangements, and concrete filling states, segment weights and correction terms are set respectively, which can reduce the application deviation of a single coefficient for complex composite beam members.

[0024] The results are verifiable: Each solution saves the component parameters, structural sections, reference coefficients, correction terms, applicable grades, and structural verification prompts, which facilitates the verification and traceability of the local structure of different composite beam components.

[0025] 3. Constructing parameter contributions and recording closed loops

[0026] Structural contribution analysis: The contribution of parameters such as wall thickness ratio, node angle, connecting plate thickness, weld size, stiffening rib spacing, diameter-to-thickness ratio, concrete filling height, and transition fillet to stress concentration factor is ranked to facilitate the determination of subsequent structural verification and local reinforcement focus.

[0027] Historical record utilization: Establish a closed-loop record that includes component type, section category, structural parameters, reference coefficients, correction items, and applicable level, supporting coefficient reuse and structural difference correction for similar steel-concrete composite truss beam components. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the adaptive solution process for the stress concentration factor of the load-bearing beam in the steel-concrete composite truss beam of the present invention;

[0029] Figure 2 This is a schematic diagram showing the correspondence between the composite section parameters of the steel-concrete composite beam bearing the beam body, the beam body sections, and the stress concentration factor correction rules in this invention.

[0030] Figure 3 This is a schematic diagram comparing the initial, corrected, and verification values ​​of the stress concentration factor of the load-bearing beam under different structural conditions in this invention;

[0031] Figure 4 This is a schematic diagram illustrating the maximum deviation change during the adaptive correction of the weight of the load-bearing beam section in this invention;

[0032] Figure 5 This is a schematic diagram showing the ranking of the contribution of key cross-sectional structural parameters to the stress concentration factor correction in this invention;

[0033] Figure 6 This is a schematic diagram illustrating the applicable situations for determining the stress concentration coefficient of a single load-bearing beam and a batch of similar composite beam components in this invention. Detailed Implementation

[0034] The technical solution of the present invention is described below with reference to embodiments. The following embodiments are used to illustrate the process of obtaining parameters of steel-concrete composite truss beam members, dividing structural sections, determining the reference stress concentration factor, adaptive correction, and outputting results, and should not be construed as limiting the specific member size, connection form, or applicable scope.

[0035] This embodiment uses the nodal region of a set of steel-concrete composite truss beam members as the object to illustrate the construction and verification process of the adaptive solution method for stress concentration factors. The example object has a main span of 60 meters, an outer diameter of 800 mm, a wall thickness of 20 mm, and the truss web members use circular steel tube sections with an outer diameter of 400 mm and a wall thickness of 16 mm.

[0036] In the parameter acquisition phase, obtaining structural component parameters is fundamental for subsequent solutions. This embodiment divides this phase into four steps: recording component geometric parameters, recording node connection parameters, recording local reinforcement parameters, and numbering component segments.

[0037] During the component geometry parameter recording stage, the outer diameter of the steel pipe, wall thickness, member section height and width, web thickness, flange thickness, node angle, section length, and member intersection position are recorded. These parameters are used to determine the wall-to-thickness ratio, diameter-to-thickness ratio, node angle grade, and node core area.

[0038] During the node connection parameter recording phase, the weld deposition width, weld leg size, weld reinforcement, connecting plate thickness, connecting plate width, bolt diameter, bolt row spacing, column spacing, and edge distance are recorded. These parameters are used to determine correction items for the connecting plate area and the weld transition zone.

[0039] During the local reinforcement parameter recording phase, the stiffening rib thickness, height, spacing, end transition radius, concrete filling height, and filling density are recorded. These parameters are used to determine the weights of the local reinforcement zone and the infill influence zone.

[0040] During the component segment numbering stage, chord pipes, branch pipes, web members, connecting plates, welds, stiffening ribs, and infill concrete are each assigned a segment number. Each segment number is stored in correspondence with its dimensional parameters, structural grade, and applicable scope for easy subsequent calculation and traceability.

[0041] The aforementioned component parameters are managed uniformly using a component record table or parameter list. Fields include component number, section number, component type, cross-sectional dimensions, connection dimensions, reinforcement dimensions, infill status, structural grade, and verification record number. After parameter recording is complete, prompts are provided for missing items and structural items outside the applicable scope.

[0042] During the segmentation process, the system divides the structural segments of the target composite beam based on structural continuity. This embodiment refines this process into four stages: node core area division, member transition area division, connection plate area division, and local reinforcement area division.

[0043] During the node core zone delineation phase, the length and width of the node core zone are determined with the intersection of the member axes and the weld envelope as the center. The node core zone is used to reflect the geometric abrupt changes and local stiffness concentrations caused by the intersection of members.

[0044] In the transition zone division stage, transition sections are set along the direction of the chord and branch pipes. The length of the transition section can be determined according to the steel pipe diameter, wall thickness, node angle, and stiffening rib end position, and is used to reflect the change of section stiffness from the node core area to the general member area.

[0045] During the sectioning of the connecting plate area, the coverage area of ​​the connecting plate, the bolt edge distance range, and the plate end transition range are included in the same structural section. Corrections for the connecting plate area are determined by the connecting plate thickness, plate width, bolt spacing, and plate end fillet radius.

[0046] During the local reinforcement zone division stage, the stiffening rib root, stiffening rib end, infill concrete boundary, and locally thickened area are respectively included in the reinforcement zone. When multiple reinforcement zones are superimposed, their weights are determined according to the main reinforcement zone and auxiliary reinforcement zones.

[0047] During the reference coefficient retrieval process, the system determines the reference stress concentration factor of the target section based on the component coefficient table. The component coefficient table is established according to structural type and parameter level, and includes at least the wall thickness ratio level, node angle level, diameter-to-thickness ratio level, connection method level, weld level, connecting plate level, and stiffening rib level.

[0048] When determining the baseline coefficients, first determine the baseline value for the core area of ​​the node, and then determine the additional corrections for the weld transition zone, connecting plate zone, and local reinforcement zone respectively. If the target parameters are between adjacent levels, a transition correction term is used to maintain the continuity of coefficient changes.

[0049] Table 1 Structural Component Parameters and Construction Grade Indicators

[0050] index numerical values unit Node core section 4 kind Member transition section 3 kind Connecting plate thickness grade 5 class Weld size grade 5 class Stiffening rib arrangement level 4 class Construction of modification terms No less than 10 item Check sample bias No more than 5 % Applicable Level Advanced, Intermediate, and Basic —

[0051] During the adaptive correction process, the system makes corrections based on the structural differences between the target component and the reference component. In this embodiment, the process includes a verification sample establishment stage, a segment weight determination stage, and an applicability level determination stage.

[0052] The selection of verification samples should cover representative cases such as reference nodes, eccentrically loaded nodes, node reinforcement structures, boundary variation structures, and high-load structures. In this embodiment, five preset verification conditions are selected: Condition 1 is the reference node condition; Condition 2 is the eccentrically loaded condition; Condition 3 is the node reinforcement condition; Condition 4 is the boundary variation condition; and Condition 5 is the high-load condition.

[0053] In the section weight determination process, the system compares the structural parameters of the target component with the baseline structural grade. Parameters such as connecting plate thickness, weld size, node angle, stiffening rib spacing, and concrete filling height each correspond to different weights. Sections with higher weights are marked as critical influence sections.

[0054] The check values ​​are used to evaluate whether the corrected stress concentration factor is applicable. Check values ​​can be derived from static load checks, strain records, comparisons with standard specimens, or historical records of similar components, and should match the joint construction and local reinforcement of the target composite beam. In this embodiment, the check values ​​for load cases 1 to 5 are 2.04, 2.10, 1.86, 2.17, and 2.24, respectively.

[0055] In the applicability level determination process, the system compares the deviation between the corrected coefficient and the verification value, and determines the applicability level based on factors such as whether the component parameters are within the applicable range, whether the key sections are complete, and whether the correction items have a basis. The first deviation threshold can be set to 5%, and the second deviation threshold can be set to 10%.

[0056] During the adaptive update phase, the system updates the segment weights, component coefficient tables, and transition correction items based on newly added component records and verification results. In this embodiment, this phase includes four stages: key segment identification, segment weight update, construction level expansion, and historical record write-back.

[0057] In terms of critical section identification, if a section corresponds to a large correction term under multiple operating conditions, or if its construction parameters are close to the applicable boundary, the system marks the section as a critical impact section. Critical impact sections are given priority for construction review or local reinforcement adjustments.

[0058] Regarding the update of section weights, if the newly added verification results show that a certain type of connecting plate, weld, or stiffening rib structure has a greater impact on the coefficient, then the weight of that type of section will be increased; if a certain type of structure has a small deviation in multiple verifications, then its correction range will be reduced and the original record will be retained.

[0059] Regarding the expansion of structural levels, when a target component has a new cross-sectional combination, connecting plate thickness level, or stiffening rib arrangement, the system saves it as a new structural level and establishes a transition correction relationship with adjacent levels.

[0060] Table 2 Comparison of initial construction coefficients and adaptive correction accuracy for 5 preset working conditions

[0061] Operating Condition 1 Reference Node 2.12 2.06 2.04 3.92 0.98 advanced Working condition 2: Eccentric loading 2.20 2.12 2.10 4.76 0.95 advanced Working Condition 3 Node Reinforcement 1.92 1.87 1.86 3.23 0.54 advanced Operating Condition 4 Boundary Change 2.26 2.19 2.17 4.15 0.92 advanced Working condition 5 High load 2.34 2.27 2.24 4.46 1.34 advanced

[0062] During the result output process, a rapid solution is performed based on the updated component coefficient table and section weights, outputting stress concentration factors, applicability levels, and structural verification prompts. In this embodiment, the process includes a target component identification stage, a result output stage, and a structural contribution analysis stage.

[0063] During the target component confirmation phase, the system reads the component parameters and section numbers of the target composite beam, and determines the reference coefficients and correction items item by item for the node core area, weld transition area, connecting plate area, and local reinforcement area. The stress concentration factor of the target working condition is 2.06, which is approximately 0.98% different from the check value of 2.04, indicating an application level of high.

[0064] During the applicability assessment phase, the system determines the applicability level based on whether the target component parameters are within the applicable range, whether there are any over-limit structures in key sections, whether the correction items have historical basis, and whether the deviation is below the threshold. If the applicability level is lower than the preset requirements, the system outputs a prompt for supplementary structural verification or adjustment of local reinforcement.

[0065] In terms of structural contribution analysis, the system can obtain the contribution of each structural parameter to the stress concentration factor by adjusting the wall thickness ratio, node angle, connecting plate thickness, weld size, stiffener spacing, and filling height item by item. The contribution ranking shows that the wall thickness ratio, node angle, connecting plate thickness, weld size, and stiffener spacing have a significant impact on the target working condition.

[0066] Table 3. Ranking of the top 8 key construction parameters by contribution

[0067] Ranking Construction parameters Physical meaning Contribution grade 1 Branch pipe to chord pipe wall thickness ratio Nodal stiffness matching +0.55 High contribution 2 Branch pipe axis included angle Member intersection pattern +0.46 High contribution 3 Connecting plate thickness Connection constraint strength +0.35 High contribution 4 Weld size Transition zone continuity +0.28 High contribution 5 Stiffening rib spacing Local enhancement effect +0.22 High contribution 6 String diameter to thickness ratio thin-walled cross-section characteristics +0.18 High contribution 7 Concrete filling height Combined force state +0.14 China's contribution 8 Transition fillets Geometric mutation mitigation +0.10 China's contribution

[0068] This embodiment also includes result storage and querying. A structural component verification record table is established, storing the component number, section number, construction parameters, reference coefficient, correction item, corrected stress concentration factor, verification value, deviation, applicable grade, and construction verification prompts for each solution in the record table. The record table supports queries based on component type, section category, construction grade, and time.

[0069] In the batch component verification mode, when it is necessary to evaluate the stress concentration factor of multiple composite beam components or multiple node sections, the system reads the structural parameters item by item according to the preset component list and automatically generates structural sections, reference factors, correction items, and applicable levels. For components that are outside the applicable range, the system marks them as requiring supplementary structural verification.

[0070] To further illustrate the adaptability of the method of the present invention in different application scenarios, the following example uses the node parameters of another set of steel-concrete composite truss beams. In this example, the main span is 50 meters, the outer diameter of the steel pipe is 600 mm, the wall thickness is 16 mm, and the truss web members adopt a circular steel pipe section with an outer diameter of 350 mm and a wall thickness of 12 mm.

[0071] In this example, the structural sections are still divided into node core areas, weld transition areas, connecting plate areas, and local reinforcement areas. Since the outer diameter and wall thickness of the web member steel pipes differ between the two examples, the stiffness of the members varies. The system updates the section weights corresponding to the wall thickness ratio, node angle, and connecting plate thickness accordingly.

[0072] The coefficient determination process follows the aforementioned component coefficient table, section weights, transition corrections, and historical verification methods. Because the outer diameter of the web member steel pipe in this example is smaller, and the local stiffness of the nodes differs from the previous example, the system updates the construction level and correction items by adding a small number of verification records.

[0073] Regarding the initial coefficients and deviation assessment, three preset working conditions were selected for verification. The initial coefficients for working conditions 1 to 3 were 1.76, 2.05, and 1.89, respectively, and the corresponding verification values ​​were 1.83, 2.12, and 1.96, respectively. The deviations were approximately 3.83%, 3.30%, and 3.57%, respectively, all of which were within the usable range.

[0074] In the adaptive correction phase, the system updates the segment weights, structural grades, and transition correction terms based on the newly added verification results. The corrected deviations are approximately 2.15%, 1.89%, and 2.04%, respectively, indicating an improved applicability level. This demonstrates that the method remains applicable to steel-concrete composite truss beams with different cross-sectional shapes.

[0075] In the output stress concentration factor step, the calculated stress concentration factor for the target working condition is 1.84, which deviates by approximately 1.08% compared to the verification value of 1.86. Structural contribution analysis shows that the thickness of the connecting plate, weld dimensions, and node angle have a significant impact on the results for this working condition.

[0076] In the results storage and batch component verification process, the system writes the component parameters, section number, reference coefficient, correction item, verification value, deviation, and applicable level for each working condition into the structural component verification record table. Batch component verification can be used to quickly filter node sections that require supplementary structural verification or local reinforcement adjustments.

[0077] In summary, this invention provides an adaptive solution method for the stress concentration factor of steel-concrete composite truss beams. By acquiring the geometric, node connection, and local reinforcement parameters of the components, the method divides the structure into structural sections according to the node core area, member intersection area, weld transition area, connecting plate area, and local reinforcement area. Based on the component coefficient table, the baseline stress concentration factor is determined, and the section weights are adaptively corrected by combining parameters such as wall thickness ratio, diameter-to-thickness ratio, node angle, connecting plate thickness, weld size, and stiffener arrangement. The method outputs the stress concentration factor, structural applicability level, key influence sections, and structural verification prompts. This invention achieves the zonal determination and adaptive correction of the stress concentration factor of steel-concrete composite truss beam components, improving the component adaptability for local stress evaluation, the traceability of the correction process, and the coefficient reuse for similar components. It can provide technical support for node structural verification, local reinforcement arrangement, and component safety evaluation. The scope of protection of this invention is defined by the appended claims and their equivalents.

Claims

1. An adaptive solution method for the stress concentration factor of a steel-concrete composite truss beam, characterized in that, Includes the following steps: Step 1: Obtain the load-bearing component parameters of the steel-concrete composite truss beam. Taking the composite section formed by the steel tube and core concrete, and the truss beam composed of chords and web members as the object, obtain the outer diameter, wall thickness, composite section size, node angle, as well as the thickness of the connecting plate, weld size, bolt arrangement, stiffening rib position, core concrete filling range and local transition structure of the chord, branch, and web members, and record the beam section to which each parameter belongs. Step 2: Divide the composite beam body into sections: Divide the load-bearing beam body of the steel-concrete composite truss into sections along the beam length according to the cross-sectional load-bearing capacity and component continuity, including chord section, branch section, node core area, member intersection area, weld transition area, connecting plate area, and local reinforcement area, and establish corresponding composite section category, size range, and applicable grade for each section; Step 3: Determine the reference stress concentration factor: Based on the combined cross-sectional form, wall thickness ratio, diameter-to-thickness ratio, node angle, and member intersection method of the beam section, determine the reference stress concentration factor of the target steel-concrete composite beam from the preset component coefficient table established based on standard component samples or historical verification results, and form the initial coefficient combination of the target load-bearing beam. Step 4: Adaptive correction: Based on the thickness of the connecting plate, weld size, stiffening rib spacing, core concrete filling height, transition fillet, structural deviation, and historical verification results, the weight of the beam section in the initial coefficient combination is adaptively corrected to obtain the corrected stress concentration coefficient of the load-bearing beam. Step 5: Output the composite beam load-bearing capacity verification results: Verify the applicable range of the corrected stress concentration factor, and output the stress concentration factor, section applicable grade, key influence section, and composite beam structure adaptation prompts of the target steel-concrete composite truss beam. This completes the zoning determination and correction of the stress concentration factor of the load-bearing beam of the steel-concrete composite truss beam.

2. The adaptive solution method for stress concentration factors of steel-concrete composite truss beams according to claim 1, characterized in that, The parameters of the load-bearing components include composite section geometric parameters, node construction parameters, and local reinforcement parameters. The composite section geometric parameters include the outer diameter of the steel pipe, wall thickness, member cross-sectional dimensions, member intersection angle, and section length. The node construction parameters include the thickness of the connecting plate, weld dimensions, bolt spacing, and edge distance. The local reinforcement parameters include the thickness, height, spacing, core concrete filling height, and transition fillet.

3. The adaptive solution method for stress concentration factors of steel-concrete composite truss beams according to claim 1, characterized in that, The beam sections are divided according to the abrupt changes in cross-sectional geometry at the nodes, abrupt changes in cross-sectional stiffness, stacking of composite cross-sectional materials, and local reinforcement arrangements; transition correction terms are set between adjacent sections to reflect the changes in local stress concentration caused by the intersection of members and abrupt changes in cross-section.

4. The adaptive solution method for stress concentration factors of steel-concrete composite truss beams according to claim 1, characterized in that, The component coefficient table is established based on the historical verification results of standard structural samples or similar load-bearing beams, including the reference stress concentration coefficients corresponding to different wall thickness ratios, node angles, diameter-to-thickness ratios, connecting plate thickness ranges, weld size ranges, and stiffening rib arrangement forms; when the target parameter is located between two adjacent structural grades, a transitional correction is made according to the section ratio.

5. The adaptive solution method for stress concentration factors of steel-concrete composite truss beams according to claim 1, characterized in that, The adaptive correction includes at least one of the following: node stiffness matching correction, weld transition correction, connecting plate constraint correction, stiffening rib reinforcement correction, core concrete filling correction, and structural deviation correction; the weight of each correction item is determined by the cross-sectional structural differences of the target load-bearing beam and the historical verification results.

6. The adaptive solution method for stress concentration factors of steel-concrete composite truss beams according to claim 1, characterized in that, The applicable levels include high, medium and low. When the structural parameters of the target load-bearing beam are all within the preset applicable range and the historical verification deviation is less than the first threshold, it is high; when some parameters are close to the applicable boundary and the historical verification deviation is less than the second threshold, it is medium; when the key structural parameters exceed the applicable range, it is low.

7. The adaptive solution method for stress concentration factors of steel-concrete composite truss beams according to claim 1, characterized in that, The adaptive correction also includes: updating the component coefficient table based on the verification results of the newly added load-bearing beams; updating the section weights based on the local strengthening effect; adjusting the transition correction items based on the structural deviation records; and establishing coefficient reuse rules for load-bearing beams of the same type based on different combined section forms.

8. The adaptive solution method for stress concentration factors of steel-concrete composite truss beams according to claim 1, characterized in that, It also includes archiving and retrieving verification results: establishing a verification record table for load-bearing beams, including composite section parameters, beam sections, reference stress concentration factors, correction items, corrected stress concentration factors, applicable levels, key influence sections, and structural adaptation prompts, and retrieving them according to component type, section category, and parameter range.

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