Design method, system, equipment and medium for box truss composite steel beam

Abstract

A box-truss composite steel beam design method, system, equipment, and medium relate to the field of bridge engineering. Specifically, the method includes determining a target main beam stiffness corresponding to a preset first bridge finite element model based on the span, vertical deflection, and lateral deflection of the target bridge; constructing a second bridge finite element model based on the target main beam stiffness; determining target bridge parameters based on the second bridge finite element model, a preset steel truss beam elevation, a preset steel box beam elevation, a preset first road surface minimum width, a preset second road surface minimum width, and a preset lateral spacing between the steel box beam and the steel truss beam; constructing a third bridge finite element model based on the target bridge parameters; and determining a target composite steel beam finite element model based on the third bridge finite element model, the normal stress and fatigue stress amplitude corresponding to the steel truss beam, and the normal stress, shear stress, stiffening rib stiffness, stiffening rib spacing, and stiffened rib plate thickness corresponding to the steel box beam and connecting crossbeam, respectively. This application can improve the computational efficiency of the box-truss composite steel beam design process.

Description

Technical Field

[0001] The present application relates to the field of bridge engineering, and specifically to a design method, system, equipment and medium for a box-truss composite steel beam. Background Art

[0002] With the growing demand for the design of long-span combined highway and railway bridges, steel truss girders and steel box girders have become common structural forms, and their design methods are relatively mature. However, as bridge spans continue to increase, traditional steel truss girders and steel box girders can no longer meet the load-bearing requirements of some ultra-long-span combined highway and railway bridges. Therefore, as a new type of steel girder, the split box truss composite steel girder has demonstrated its potential application value in ultra-long-span combined highway and railway cable-supported bridges.

[0003] However, the structure of the separated box-girder composite steel beam is relatively complex. In the traditional design process, it is usually necessary to consider multiple factors such as the strength, stiffness and stability of the structure at the same time, coordinate the relationship between the individual forces of the box and girder and the overall force, and conduct repeated calculations based on the spatial layout of the structure, resulting in low calculation efficiency.

[0004] Therefore, how to provide a design method for box truss composite steel beams to improve the calculation efficiency in the design process is an urgent problem that needs to be solved. Summary of the Invention

[0005] The present application provides a box-truss composite steel beam design method, system, equipment and medium, which can improve the calculation efficiency of the box-truss composite steel beam during the design process.

[0006] In a first aspect, an embodiment of the present application provides a method for designing a box-truss composite steel beam, the method comprising:

[0007] Determining a target main beam stiffness corresponding to a preset first bridge finite element model based on the span, vertical deflection, and lateral deflection of the target bridge;

[0008] constructing a second bridge finite element model based on the target main beam stiffness, and determining target bridge parameters based on the second bridge finite element model, a preset steel truss girder elevation, a preset steel box girder elevation, a preset first road surface minimum width, a preset second road surface minimum width, and a preset transverse spacing between the steel box girder and the steel truss girder, the target bridge parameters including a target girder height and a target girder width corresponding to the steel truss girder, a first target beam height and a first target beam width corresponding to the steel box girder, and a second target beam height and a second target beam width corresponding to a connecting crossbeam, the connecting crossbeam being used to connect the steel truss girder and the steel box girder;

[0009] A third bridge finite element model is constructed based on the target bridge parameters, and a target composite steel beam finite element model is determined based on the third bridge finite element model, the normal stress and fatigue stress amplitude corresponding to the steel truss beam, and the normal stress, shear stress, stiffening rib stiffness, stiffening rib spacing, and stiffened rib plate thickness corresponding to the steel box beam and the connecting crossbeam, respectively.

[0010] In conjunction with the first aspect, in one embodiment, the first bridge finite element model includes a preset first main beam stiffness, and determining the target main beam stiffness corresponding to the first bridge finite element model based on the span, vertical deflection, and lateral deflection of the target bridge includes:

[0011] Taking the quotient of the vertical deflection and the span to obtain a vertical deflection ratio;

[0012] Taking the quotient of the lateral deflection and the span to obtain a lateral deflection ratio;

[0013] If the vertical deflection ratio is not greater than a preset vertical deflection ratio threshold and the lateral deflection ratio is not greater than a preset lateral deflection ratio threshold, the first main beam stiffness is used as the target main beam stiffness.

[0014] In combination with the first aspect, in one embodiment, the first main beam stiffness includes X-direction moment of inertia, Y-direction moment of inertia, and Z-direction moment of inertia. After the step of performing a quotient processing on the lateral deflection and the span to obtain the lateral deflection ratio, the method further includes:

[0015] If the vertical deflection ratio is greater than the preset vertical deflection ratio threshold, the Y-direction moment of inertia is increased until the vertical deflection ratio is no greater than the preset vertical deflection ratio threshold, and the main beam stiffness corresponding to the increased Y-direction moment of inertia is used as the target main beam stiffness;

[0016] If the lateral deflection ratio is greater than the preset lateral deflection ratio threshold, the Z-direction moment of inertia is increased until the lateral deflection ratio is no greater than the preset lateral deflection ratio threshold, and the main beam stiffness corresponding to the increased Z-direction moment of inertia is used as the target main beam stiffness.

[0017] In combination with the first aspect, in one embodiment, constructing the second bridge finite element model based on the target main beam stiffness includes:

[0018] Determining first bridge parameters based on the target main beam stiffness, the first bridge parameters including a first truss height and a first truss width corresponding to the steel truss beam, a first beam height and a first beam width corresponding to the steel box beam, and a second beam height and a second beam width corresponding to the connecting crossbeam;

[0019] A second bridge finite element model is constructed based on the first bridge parameters.

[0020] In conjunction with the first aspect, in one embodiment, determining the target bridge parameters based on the second bridge finite element model, a preset steel truss girder elevation, a preset steel box girder elevation, a preset first road surface minimum width, a preset second road surface minimum width, and a preset transverse spacing between the steel box girder and the steel truss girder includes:

[0021] If the difference between the first truss height and the first beam height is equal to the difference between the steel truss elevation and the steel box beam elevation, the first truss width is not less than the minimum width of the first road surface, the first beam width is not less than the minimum width of the second road surface, the lateral spacing between the steel box beam and the steel truss beam is greater than the preset lateral spacing of the tower bridge, the vertical deflection ratio is not greater than the preset vertical deflection ratio threshold, the lateral deflection ratio is not greater than the preset lateral deflection ratio threshold, and the normal stress of each component of the combined steel beam is not greater than the preset normal stress threshold, then the first bridge parameter is used as the target bridge parameter, and the combined steel beam includes a steel box beam, a steel truss beam, and a connecting crossbeam.

[0022] In combination with the first aspect, in one embodiment, constructing a third bridge finite element model based on the target bridge parameters includes:

[0023] Calculating a first stiffness corresponding to the steel truss girder, a second stiffness corresponding to the steel box girder, and a third stiffness corresponding to the connecting beam based on the target bridge parameters;

[0024] constructing a third bridge finite element model based on the first stiffness, the second stiffness, the third stiffness, and target bridge parameters;

[0025] The steel truss in the finite element model of the third bridge is simulated as a beam element, wherein the upper and lower chords of the steel truss are box-shaped and the web is I-shaped;

[0026] The steel box girder and the connecting cross beam in the third bridge finite element model are simulated according to the plate element, and the stiffening rib type of the steel box girder and the connecting cross beam is longitudinal stiffening rib or transverse stiffening rib.

[0027] In conjunction with the first aspect, in one embodiment, determining the target composite steel beam finite element model based on the third bridge finite element model, the normal stress and fatigue stress amplitude corresponding to the steel truss girder, and the normal stress, shear stress, stiffening rib stiffness, stiffening rib spacing, and stiffened rib plate thickness corresponding to the steel box girder and the connecting crossbeam, respectively, includes:

[0028] For each member of the steel truss girder, if the first normal stress corresponding to the steel truss girder is not greater than a preset first normal stress threshold, the first normal stress is less than a preset reduced stress value, and the fatigue stress amplitude is not greater than a preset fatigue stress amplitude threshold, then the first stiffness is used as the target steel truss girder stiffness;

[0029] For each plate member of the steel box girder, if the second normal stress corresponding to the steel box girder is not greater than a preset second normal stress threshold, the first shear stress corresponding to the steel box girder is not greater than a preset first shear stress threshold, the first stiffening rib stiffness corresponding to the steel box girder is not less than a preset first stiffening rib stiffness threshold, and the ratio of the first stiffening rib spacing corresponding to the steel box girder to the thickness of the first stiffened plate is not greater than a preset first ratio threshold, then the second stiffness is used as the target steel box girder stiffness;

[0030] For each plate member of the connecting beam, if the third normal stress corresponding to the connecting beam is not greater than a preset third normal stress threshold, the second shear stress corresponding to the connecting beam is not greater than a preset second shear stress threshold, the second stiffening rib stiffness corresponding to the connecting beam is not less than a preset second stiffening rib stiffness threshold, and the ratio of the second stiffening rib spacing corresponding to the connecting beam to the thickness of the second stiffened plate is not greater than a preset second ratio threshold, then the third stiffness is used as the target connecting beam stiffness;

[0031] The target composite steel beam finite element model is constructed based on the target steel truss stiffness, target steel box beam stiffness and target connecting beam stiffness.

[0032] In a second aspect, an embodiment of the present application provides a box-truss composite steel beam design system, the box-truss composite steel beam design system comprising:

[0033] A first processing module is configured to determine a target main beam stiffness corresponding to a preset first bridge finite element model based on the span, vertical deflection, and lateral deflection of the target bridge;

[0034] a second processing module, which is used to construct a second bridge finite element model based on the target main beam stiffness, and determine target bridge parameters based on the second bridge finite element model, a preset steel truss girder elevation, a preset steel box girder elevation, a preset first road surface minimum width, a preset second road surface minimum width, and a preset transverse spacing between the steel box girder and the steel truss girder, the target bridge parameters including a target girder height and a target girder width corresponding to the steel truss girder, a first target beam height and a first target beam width corresponding to the steel box girder, and a second target beam height and a second target beam width corresponding to a connecting crossbeam, the connecting crossbeam being used to connect the steel truss girder and the steel box girder;

[0035] The third processing module is used to construct a third bridge finite element model based on the target bridge parameters, and determine the target combined steel beam finite element model based on the third bridge finite element model, the normal stress and fatigue stress amplitude corresponding to the steel truss beam, and the normal stress, shear stress, stiffening rib stiffness, stiffening rib spacing, and stiffened rib plate thickness corresponding to the steel box beam and the connecting crossbeam respectively.

[0036] In a third aspect, an embodiment of the present application provides a box girder composite steel beam design device, which includes a processor, a memory, and a box girder composite steel beam design program stored in the memory and executable by the processor, wherein when the box girder composite steel beam design program is executed by the processor, the steps of the box girder composite steel beam design method as described in any of the above items are implemented.

[0037] In a fourth aspect, an embodiment of the present application provides a computer-readable storage medium, on which a box girder composite steel beam design program is stored, wherein when the box girder composite steel beam design program is executed by a processor, the steps of the box girder composite steel beam design method as described in any of the above items are implemented.

[0038] The beneficial effects of the technical solutions provided in the embodiments of the present application include:

[0039] The target main beam stiffness corresponding to the preset first bridge finite element model is determined based on the span, vertical deflection and lateral deflection of the target bridge; a second bridge finite element model is constructed based on the target main beam stiffness, and the target truss height and target truss width corresponding to the steel truss, the first target beam height and the first target beam width corresponding to the steel box beam, and the second target beam height and the second target beam width corresponding to the connecting beam are determined based on the second bridge finite element model, the preset steel truss elevation, the preset steel box beam elevation, the preset first minimum road surface width, the preset second minimum road surface width, and the preset lateral spacing between the steel box beam and the steel truss, and the connecting beam is used to connect the steel truss beam and the steel box beam; a third bridge finite element model is constructed based on the target bridge parameters, and a target combined steel beam finite element model is determined based on the third bridge finite element model, the normal stress and fatigue stress amplitude corresponding to the steel truss, and the normal stress, shear stress, stiffening rib stiffness, stiffening rib spacing, and stiffened rib plate thickness corresponding to the steel box beam and the connecting beam, respectively. This application optimizes the performance of the bridge through simulation analysis without the need for extensive physical testing or repeated calculations, which not only improves computational efficiency but also reduces design and time costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 This is a flow chart of an embodiment of the method for designing a box truss composite steel beam of the present application;

[0041] Figure 2 Schematic diagram of a box-truss composite steel beam in an embodiment of the design method for a box-truss composite steel beam of the present application;

[0042] Figure 3 Schematic diagram of the truss height, beam height, and transverse spacing between the steel truss beam and the steel box beam in an embodiment of the design method for box-truss composite steel beams of this application;

[0043] Figure 4Schematic diagram of the truss width, beam width, and transverse spacing between the steel truss beam and the steel box beam in an embodiment of the design method for box-truss composite steel beams of the present application;

[0044] Figure 5 This is a schematic diagram of the functional modules of an embodiment of the box truss composite steel beam design system of the present application;

[0045] Figure 6 Schematic diagram of the hardware structure of the box girder composite steel beam design equipment involved in the embodiment of this application;

[0046] Among them, 1. Steel truss; 2. Steel box girder; 3. Connecting beam; 4. Tower bridge. DETAILED DESCRIPTION

[0047] In order to enable those skilled in the art to better understand the present invention, the following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0048] In order to make the objectives, technical solutions and advantages of this application clearer, the implementation methods of this application will be further described in detail below with reference to the accompanying drawings.

[0049] In a first aspect, an embodiment of the present application provides a method for designing a box truss composite steel beam.

[0050] In one embodiment, referring to Figure 1 , Figure 1 This is a flow chart of an embodiment of the design method of a box truss composite steel beam of this application. Figure 1 As shown in Figure 2, the design method of box truss composite steel beams includes:

[0051] Step S10: Determine the target main beam stiffness corresponding to the preset first bridge finite element model based on the span, vertical deflection, and lateral deflection of the target bridge.

[0052] For example, in an embodiment of the present application, the preset first bridge finite element model can be determined according to actual needs and is not limited here. For example, the main beam in the first bridge finite element model (i.e., the first-level model) can be simulated according to a single-beam model; the target bridge refers to the bridge to be analyzed, and the span of the target bridge directly affects the force distribution of the main beam. The vertical deflection reflects the elastic deformation of the main beam in the vertical direction, and the lateral deflection describes the degree of deformation of the main beam in the horizontal direction.

[0053] Specifically, the deformation range of the main beam under stress conditions can be determined based on the span of the bridge. The main beam stiffness can be calculated by combining the vertical deflection and the lateral deflection through the finite element analysis method to ensure that the deformation of the bridge under the design load meets the requirements of the specification. Then, by comparing with the preset first bridge finite element model, the main beam stiffness is further adjusted to obtain the target main beam stiffness to meet the target design requirements and ensure the safety, stability and performance of the bridge structure. It should be understood that the principles of the finite element analysis method are common knowledge in this field and will not be repeated here for the sake of brevity.

[0054] Step S20: Construct a second bridge finite element model based on the target main beam stiffness, and determine target bridge parameters based on the second bridge finite element model, a preset steel truss beam elevation, a preset steel box beam elevation, a preset first road surface minimum width, a preset second road surface minimum width, and a preset transverse spacing between the steel box beam and the steel truss beam. The target bridge parameters include a target beam height and a target beam width corresponding to the steel truss beam, a first target beam height and a first target beam width corresponding to the steel box beam, and a second target beam height and a second target beam width corresponding to the connecting beam, where the connecting beam is used to connect the steel truss beam and the steel box beam.

[0055] For example, in the embodiment of the present application, refer to Figure 2 As shown, the various component structures of the box girder composite steel beam include a steel truss beam 1, a steel box girder 2 and a connecting crossbeam 3, wherein the connecting crossbeam 3 is used to connect the steel truss beam 1 and the steel box girder 2; the specific values ​​of the preset steel truss beam elevation, the preset steel box girder elevation, and the preset transverse spacing between the steel box girder and the steel truss beam can be determined according to actual needs and are not limited here; the preset first minimum road surface width and the preset second minimum road surface width are determined by the number of traffic lanes and are not limited here; the target bridge parameters (i.e., bridge design parameters) include the target girder height and target girder width corresponding to the steel truss beam 1, the first target beam height and the first target beam width corresponding to the steel box girder 2, and the second target beam height and the second target beam width corresponding to the connecting crossbeam 3.

[0056] Specifically, based on the target main beam stiffness, the main beam's geometry, material properties, and boundary conditions can be defined in the finite element model to simulate the deformation and stress distribution of the main beam under different loads. The basic dimensions of the various component structures of the box-girder composite steel beam are then adjusted according to the target main beam stiffness to ensure that the bridge's structural stiffness, bearing capacity, and functional use are consistent with the design objectives of the target main beam. Ultimately, a second bridge finite element model (i.e., a secondary model) that meets the requirements is constructed to provide an accurate basis for bridge performance prediction and optimized design.

[0057] It should be noted that after the second bridge finite element model is constructed, the relative position between steel truss girder 1 and steel box girder 2 can be determined by the preset steel truss girder elevation and steel box girder elevation, thereby rationally arranging the longitudinal layout of the bridge; at the same time, the preset minimum width of the first road surface and the minimum width of the second road surface are taken into account to ensure that the bridge deck width meets the traffic requirements; and then the lateral spacing between steel truss girder 1 and steel box girder 2 is used to ensure that the connection and bearing performance between the two meet the design requirements, and finally determine the target bridge parameters. The above process comprehensively considers factors such as truss height, truss width, beam height, beam width, and lateral spacing, and optimizes various bridge design parameters to ensure that the overall stiffness, strength, and functional requirements of the box truss composite steel beam are met.

[0058] Step S30: Construct a third bridge finite element model based on the target bridge parameters, and determine a target composite steel beam finite element model based on the third bridge finite element model, the normal stress and fatigue stress amplitude corresponding to the steel truss beam, and the normal stress, shear stress, stiffening rib stiffness, stiffening rib spacing, and stiffened rib plate thickness corresponding to the steel box beam and the connecting crossbeam, respectively.

[0059] For example, in the embodiment of the present application, normal stress refers to the stress in any direction of a material or structure when it is subjected to stress, and fatigue stress amplitude refers to the difference between the maximum normal stress and the minimum normal stress to which the material or structure is subjected in a load cycle, that is, fatigue stress amplitude = σ max -σ min , where σ max is the maximum normal stress, σ min is the minimum normal stress; the stiffener is a reinforcing structure in the steel box beam or connecting beam used to enhance the bearing capacity and prevent the plate from warping or instability. The stiffener stiffness refers to the contribution of the stiffener to the structural rigidity. The greater the stiffness, the better the overall stability and bearing capacity of the beam. Among them, the stiffener stiffness I r =b r δ r 3 γ / 11,b r is the stiffener width, δ r is the stiffening rib thickness, γ is the stiffness ratio; the stiffening rib spacing refers to the distance between two adjacent stiffening ribs in the steel box girder or connecting beam. The stiffening rib spacing needs to be reasonably designed to ensure the stability of the beam and avoid material waste caused by too dense stiffening ribs; the stiffened rib plate thickness refers to the thickness of the plate in the steel box girder or connecting beam that works together with the stiffening ribs. The plate thickness is crucial to the strength and stability of the beam. Too thin may cause local buckling or fatigue failure, while too thick will increase weight and cost.

[0060] Specifically, the target bridge parameters are input into the bridge finite element model to construct the third bridge finite element model (i.e., the third-level model) to accurately simulate the overall structure and local stress distribution of the bridge; the third bridge finite element model is then used to conduct detailed stress analysis, stability judgment, and fatigue performance judgment on each member of the steel truss beam in combination with the normal stress and fatigue stress amplitude associated with the steel truss beam; and the normal stress, shear stress, stiffening rib stiffness, stiffening rib spacing, stiffening rib plate thickness, and other mechanical parameters corresponding to the steel box beam are combined to conduct detailed positive stress analysis on each plate of the steel box beam. Force analysis, shear analysis, stiffening rib stiffness analysis, and local stability analysis of the stiffened rib plates; combined with the mechanical parameters such as normal stress, shear stress, stiffening rib stiffness, stiffening rib spacing, and stiffened rib plate thickness corresponding to the connecting beam, a detailed normal stress analysis, shear analysis, stiffening rib stiffness analysis, and local stability analysis of the stiffened rib plates were performed on each plate of the connecting beam; based on the analysis results, the design parameters in the third bridge finite element model were optimized, and finally the target composite steel beam finite element model was determined, thus laying the foundation for the safety and durability analysis of the bridge.

[0061] The present application determines the target main beam stiffness corresponding to a preset first bridge finite element model based on the span, vertical deflection, and lateral deflection of the target bridge; constructs a second bridge finite element model based on the target main beam stiffness, and determines the target truss height and target truss width corresponding to the steel truss, the first target beam height and the first target beam width corresponding to the steel box beam, and the second target beam height and the second target beam width corresponding to the connecting beam based on the second bridge finite element model, the preset steel truss elevation, the preset steel box beam elevation, the preset first minimum road surface width, the preset second minimum road surface width, and the preset lateral spacing between the steel box beam and the steel truss, wherein the connecting beam is used to connect the steel truss and the steel box beam; constructs a third bridge finite element model based on the target bridge parameters, and determines the target combined steel beam finite element model based on the third bridge finite element model, the normal stress and fatigue stress amplitude corresponding to the steel truss, and the normal stress, shear stress, stiffening rib stiffness, stiffening rib spacing, and stiffened rib plate thickness corresponding to the steel box beam and the connecting beam, respectively. This application optimizes the performance of the bridge through simulation analysis without the need for extensive physical testing or repeated calculations, which not only improves computational efficiency but also reduces design and time costs.

[0062] Furthermore, in one embodiment, the first bridge finite element model includes a preset first main beam stiffness, and determining the target main beam stiffness corresponding to the first bridge finite element model based on the span, vertical deflection, and lateral deflection of the target bridge includes:

[0063] Taking the quotient of the vertical deflection and the span to obtain a vertical deflection ratio;

[0064] Taking the quotient of the lateral deflection and the span to obtain a lateral deflection ratio;

[0065] If the vertical deflection ratio is not greater than a preset vertical deflection ratio threshold and the lateral deflection ratio is not greater than a preset lateral deflection ratio threshold, the first main beam stiffness is used as the target main beam stiffness.

[0066] Exemplarily, in an embodiment of the present application, the finite element model of the first bridge includes a preset first main beam stiffness. The specific values ​​of the preset vertical deflection ratio threshold and the preset lateral deflection ratio threshold can be determined based on engineering specifications or safety standards, aiming to ensure the reliability of the bridge in terms of bearing capacity and performance. No limitation is made here. For example, the preset vertical deflection ratio threshold (i.e., the allowable vertical deflection ratio) can preferably be 1 / 300, and the preset lateral deflection span ratio threshold (i.e., the allowable lateral deflection ratio) can preferably be 1 / 150.

[0067] Specifically, the vertical deflection and span are substituted into the following formula to obtain the vertical deflection ratio, which is as follows:

[0068]

[0069] Where v is the vertical deflection, is the vertical deflection ratio, and L is the span.

[0070] Substituting the lateral deflection and span into the following formula yields the lateral deflection ratio, which is calculated as follows:

[0071]

[0072] Where h is the lateral deflection, is the lateral deflection ratio.

[0073] It should be noted that after calculating the vertical deflection ratio and the lateral deflection ratio, and comparing the vertical deflection with the preset vertical deflection threshold, and the lateral deflection with the preset lateral deflection threshold, if the vertical deflection ratio is ≤ the preset vertical deflection ratio threshold and the lateral deflection ratio is ≤ the preset lateral deflection ratio threshold, it means that the design meets the deformation requirements, indicating that the stiffness of the bridge is sufficient to meet normal use needs; in this case, the stiffness of the first main beam in the finite element model of the first bridge can be used as the target main beam stiffness to ensure the stability and safety of the structure, while avoiding excessive increase in unnecessary stiffness, thereby achieving a balance between economy and safety.

[0074] Furthermore, in one embodiment, the first main beam stiffness includes X-direction moment of inertia, Y-direction moment of inertia, and Z-direction moment of inertia. After the step of performing a quotient processing on the lateral deflection and the span to obtain the lateral deflection ratio, the method further includes:

[0075] If the vertical deflection ratio is greater than the preset vertical deflection ratio threshold, the Y-direction moment of inertia is increased until the vertical deflection ratio is no greater than the preset vertical deflection ratio threshold, and the main beam stiffness corresponding to the increased Y-direction moment of inertia is used as the target main beam stiffness;

[0076] If the lateral deflection ratio is greater than the preset lateral deflection ratio threshold, the Z-direction moment of inertia is increased until the lateral deflection ratio is no greater than the preset lateral deflection ratio threshold, and the main beam stiffness corresponding to the increased Z-direction moment of inertia is used as the target main beam stiffness.

[0077] For example, in an embodiment of the present application, the first main beam stiffness includes the X-direction moment of inertia, the Y-direction moment of inertia, and the Z-direction moment of inertia. Specifically, when judging the vertical deflection ratio and the lateral deflection, if the vertical deflection ratio is greater than the preset vertical deflection ratio threshold, it means that the vertical deflection is too large. The vertical stiffness can be increased by increasing the vertical moment of inertia of the main beam (Y-direction moment of inertia), thereby reducing the vertical deflection until the vertical deflection ratio meets the specification requirements (i.e., the vertical deflection ratio ≤ the preset vertical deflection ratio threshold); at this time, the main beam stiffness corresponding to the increased Y-direction moment of inertia can be used as the new target main beam stiffness to ensure that the vertical deformation is controlled within a reasonable range.

[0078] It can be understood that if the lateral deflection ratio exceeds the preset lateral deflection ratio threshold, indicating excessive lateral deflection, the lateral stiffness can be increased by increasing the main beam's lateral moment of inertia (Z-direction moment of inertia), thereby reducing the lateral deflection until the lateral deflection ratio meets the design standard (i.e., the lateral deflection ratio ≤ the preset lateral deflection ratio threshold). At this point, the main beam stiffness corresponding to the increased Z-direction moment of inertia can be used as the new target main beam stiffness to ensure that lateral deformation is also effectively controlled. The entire process ensures that the bridge's vertical and lateral deflections meet the design requirements by gradually adjusting the main beam stiffness (specifically, adjusting the Y-direction and Z-direction moments of inertia), thereby achieving a balance between the bridge's structural safety and economic efficiency.

[0079] Furthermore, in one embodiment, constructing the second bridge finite element model based on the target main beam stiffness includes:

[0080] Determining first bridge parameters based on the target main beam stiffness, the first bridge parameters including a first truss height and a first truss width corresponding to the steel truss beam, a first beam height and a first beam width corresponding to the steel box beam, and a second beam height and a second beam width corresponding to the connecting crossbeam;

[0081] A second bridge finite element model is constructed based on the first bridge parameters.

[0082] Exemplarily, in an embodiment of the present application, the first bridge parameter reflects the geometric dimensions of each component and is the basis of the bridge stiffness, stability and bearing capacity, which includes the first truss height and first truss width corresponding to the steel truss, the first beam height and first beam width corresponding to the steel box beam, and the second beam height and second beam width corresponding to the connecting beam.

[0083] It should be noted that during the bridge design process, the basic dimensions of each component structure of the box-truss composite steel beam (i.e., the first bridge parameters) are set according to the target main beam stiffness. These reflect the geometric dimensions and shapes of the bridge components and provide a basis for subsequent design. The geometric dimensions and physical properties (such as material properties, density, elastic modulus, etc.) of the steel truss beam, steel box beam, and connecting beam are then input into the finite element model. Combined with the stiffness requirements of the target main beam, the component properties are set and the constraints are defined, thereby achieving accurate simulation and analysis of the entire bridge structure, and ultimately obtaining the second bridge finite element model.

[0084] Specifically, refer to Figure 3 and Figure 4 As shown, the steel truss is simulated as a longitudinal single beam model, and its outline size is the first truss height h1×first truss width b1. The steel box girder is simulated as a longitudinal single beam model, and its outline size is the first beam height h2×first beam width b2. Each connecting crossbeam is simulated as a transverse single beam model, and its outline size is the second beam height h3×second beam width b3. The transverse spacing between the steel truss and the steel box girder is S.

[0085] It can be understood that the embodiment of the present application analyzes the influence of the box truss composite steel beam on the overall stiffness, stress state and structural response by adjusting the first bridge parameter, and then optimizes the design of the bridge to ensure its safety, stability and economy in actual use.

[0086] Furthermore, in one embodiment, determining the target bridge parameters based on the second bridge finite element model, the preset steel truss girder elevation, the preset steel box girder elevation, the preset first road surface minimum width, the preset second road surface minimum width, and the preset transverse spacing between the steel box girder and the steel truss girder includes:

[0087] If the difference between the first truss height and the first beam height is equal to the difference between the steel truss elevation and the steel box beam elevation, the first truss width is not less than the minimum width of the first road surface, the first beam width is not less than the minimum width of the second road surface, the lateral spacing between the steel box beam and the steel truss beam is greater than the preset lateral spacing of the tower bridge, the vertical deflection ratio is not greater than the preset vertical deflection ratio threshold, the lateral deflection ratio is not greater than the preset lateral deflection ratio threshold, and the normal stress of each component of the combined steel beam is not greater than the preset normal stress threshold, then the first bridge parameter is used as the target bridge parameter, and the combined steel beam includes a steel box beam, a steel truss beam, and a connecting crossbeam.

[0088] For example, in the embodiment of the present application, the specific values ​​of the preset transverse spacing of the tower bridge and the preset normal stress threshold can be determined according to actual needs and are not limited here; specifically, in the process of determining the target bridge parameters, the geometric and mechanical characteristics of the bridge need to be analyzed in detail, wherein the difference between the first truss height and the first beam height must be equal to the difference between the steel truss beam elevation and the steel box beam elevation. This condition ensures the height matching of the box girder composite steel beam in the vertical structure, thereby ensuring overall stability; the first truss width must be ≥ the minimum width of the first road surface, and the first beam width must be ≥ the minimum width of the second road surface. These conditions ensure that the transverse dimensions of the bridge meet the traffic Load requirements, that is, it can accommodate passing vehicles and pedestrians; the lateral spacing between the steel box girder and the steel truss girder must be greater than the preset lateral spacing of the tower bridge. This requirement can effectively avoid the lateral squeezing effect and ensure the stability and durability of the structure; at the same time, in order to control the stiffness and deformation of the structure, the vertical deflection ratio must be ≤ the preset vertical deflection ratio threshold, and the lateral deflection ratio must be ≤ the preset lateral deflection ratio threshold, to ensure that the deformation of the bridge under load meets the use requirements and prevent functional failure caused by excessive deformation; the positive stress of each component of the box-truss composite steel beam must be ≤ the preset positive stress threshold to avoid premature fatigue or damage of the material due to excessive stress concentration.

[0089] It should be noted that only when all the above conditions are met can the parameters of the first bridge be used as the design parameters of the target bridge (i.e., target bridge parameters), so as to ensure the comprehensive optimization of the target bridge in terms of structural safety, durability and functionality; if a certain condition is not met, the parameter size corresponding to the condition can be adjusted until the parameter meets the design requirements; specifically, if the difference between the first truss height and the first beam height does not meet the requirements, the height of the truss or beam can be increased or decreased to ensure that the height difference between the two is consistent with the difference between the steel truss beam elevation and the steel box beam elevation; if the first truss width is not sufficient to meet the minimum width requirement of the first road surface, the first truss width can be increased. At the same time, if the first beam width If it is not enough to meet the minimum width requirement of the second pavement, the first beam width can be increased; if the vertical deflection ratio does not meet the requirement, the vertical deflection ratio can be optimized by increasing the Y-direction moment of inertia until the vertical deflection is ≤ the preset vertical deflection ratio threshold; if the lateral deflection ratio does not meet the requirement, the lateral deflection ratio can be optimized by increasing the Z-direction moment of inertia until the lateral deflection is ≤ the preset lateral deflection ratio threshold; if the lateral spacing between the steel truss and the steel box girder is insufficient, the lateral spacing can be adjusted to ensure that it is greater than the preset tower bridge lateral spacing; if the normal stress of certain components exceeds the preset threshold, the stress concentration can be reduced by optimizing the component geometry or selecting higher strength materials to ensure that it is within a safe range.

[0090] Furthermore, in one embodiment, constructing a third bridge finite element model based on the target bridge parameters includes:

[0091] Calculating a first stiffness corresponding to the steel truss girder, a second stiffness corresponding to the steel box girder, and a third stiffness corresponding to the connecting beam based on the target bridge parameters;

[0092] constructing a third bridge finite element model based on the first stiffness, the second stiffness, the third stiffness, and target bridge parameters;

[0093] The steel truss in the finite element model of the third bridge is simulated as a beam element, wherein the upper and lower chords of the steel truss are box-shaped and the web is I-shaped;

[0094] The steel box girder and the connecting cross beam in the third bridge finite element model are simulated according to the plate element, and the stiffening rib type of the steel box girder and the connecting cross beam is longitudinal stiffening rib or transverse stiffening rib.

[0095] For example, in an embodiment of the present application, a finite element analysis method can be used to calculate a first stiffness corresponding to the steel truss, a second stiffness corresponding to the steel box girder, and a third stiffness corresponding to the connecting crossbeam based on the target bridge parameters. After calculating the stiffness of each structure, a finite element model is established based on these stiffness values ​​and the target bridge parameters, and the overall analysis of the bridge is performed. In the third bridge finite element model, the steel truss is simulated using beam elements, and the upper and lower chords of the steel truss are proposed to be box-shaped, and the web is proposed to be I-shaped, and the contribution of the box sections of the upper and lower chords and the I-shaped section of the web to the structural stiffness is fully considered. The steel box girder and the connecting crossbeam are simulated using plate elements, and the stiffening rib types of the steel box girder and the connecting crossbeam are proposed to be longitudinal stiffening ribs or transverse stiffening ribs, and the cross section is the actual cross section, further refining the influence of the stiffening ribs to ensure that the contribution of the longitudinal stiffening ribs or transverse stiffening ribs to the stability of the bridge is accurately reflected.

[0096] It should be noted that if the stiffness results calculated through finite element analysis do not meet the first stiffness, second stiffness, or third stiffness requirements of the third bridge finite element model, the proposed results must be adjusted, for example by modifying the cross-sectional dimensions, optimizing the stiffening rib layout, or adjusting the material properties, so that the structure reaches the desired stiffness target, thereby ensuring the safety and stability of the overall bridge structure. Through the above-mentioned modeling and analysis, the embodiments of the present application can achieve a comprehensive assessment of the performance of the bridge structure, optimize the design scheme, and ensure the safety and functionality of the structure.

[0097] Furthermore, in one embodiment, determining the target composite steel beam finite element model based on the third bridge finite element model, the normal stress and fatigue stress amplitude corresponding to the steel truss girder, and the normal stress, shear stress, stiffening rib stiffness, stiffening rib spacing, and stiffened rib plate thickness corresponding to the steel box girder and the connecting crossbeam, respectively, includes:

[0098] For each member of the steel truss girder, if the first normal stress corresponding to the steel truss girder is not greater than a preset first normal stress threshold, the first normal stress is less than a preset reduced stress value, and the fatigue stress amplitude is not greater than a preset fatigue stress amplitude threshold, then the first stiffness is used as the target steel truss girder stiffness;

[0099] For each plate member of the steel box girder, if the second normal stress corresponding to the steel box girder is not greater than a preset second normal stress threshold, the first shear stress corresponding to the steel box girder is not greater than a preset first shear stress threshold, the first stiffening rib stiffness corresponding to the steel box girder is not less than a preset first stiffening rib stiffness threshold, and the ratio of the first stiffening rib spacing corresponding to the steel box girder to the thickness of the first stiffened plate is not greater than a preset first ratio threshold, then the second stiffness is used as the target steel box girder stiffness;

[0100] For each plate member of the connecting beam, if the third normal stress corresponding to the connecting beam is not greater than a preset third normal stress threshold, the second shear stress corresponding to the connecting beam is not greater than a preset second shear stress threshold, the second stiffening rib stiffness corresponding to the connecting beam is not less than a preset second stiffening rib stiffness threshold, and the ratio of the second stiffening rib spacing corresponding to the connecting beam to the thickness of the second stiffened plate is not greater than a preset second ratio threshold, then the third stiffness is used as the target connecting beam stiffness;

[0101] The target composite steel beam finite element model is constructed based on the target steel truss stiffness, target steel box beam stiffness and target connecting beam stiffness.

[0102] For example, in an embodiment of the present application, the specific values ​​of the preset first normal stress threshold, the preset second normal stress threshold, the preset third normal stress threshold, the preset reduced stress value, the preset fatigue stress amplitude threshold, the preset first shear stress, the preset second shear stress, the preset first stiffening rib stiffness threshold, and the preset second stiffening rib stiffness threshold can be determined according to actual needs and are not limited here.

[0103] Specifically, after constructing the finite element model of the third bridge, each member corresponding to the steel truss, each plate corresponding to the steel box girder, and each plate corresponding to the connecting crossbeam must be analyzed one by one to ensure that the corresponding structural mechanics requirements are met. For each member of the steel truss, determine whether its corresponding first normal stress is ≤ the preset first normal stress threshold (i.e., the first allowable normal stress), whether the first normal stress is < the preset reduced stress value φ[σ], and whether the fatigue stress amplitude is ≤ the preset fatigue stress amplitude threshold. If all of the above conditions are met, the first stiffness of the member can be used as the target steel truss stiffness. If any of the above conditions is not met, the corresponding parameter can be adjusted until it meets the design requirements. Specifically, if the first normal stress is greater than the preset first normal stress threshold, the stress can be dispersed by increasing the cross-sectional area of ​​the stressed area, thereby reducing the first stress. If the first normal stress is ≥ the preset reduced stress value, materials with better fatigue resistance can be used. If the fatigue stress amplitude is greater than the preset fatigue stress amplitude threshold, design measures such as reasonable geometry, smooth transitions, and avoiding sharp corners can be used to reduce fatigue stress concentration in the structure, thereby reducing the fatigue stress amplitude.

[0104] It should be noted that for each plate of the steel box girder, it is necessary to verify whether its corresponding second normal stress is ≤ the preset second normal stress threshold (i.e., the second allowable normal stress), whether the first shear stress is ≤ the preset first shear stress threshold (i.e., the first allowable shear stress), whether the stiffness of the first stiffening rib is ≥ the preset first stiffening rib stiffness threshold, and whether the ratio between the first stiffening rib spacing and the first stiffened plate thickness is ≤ the preset first ratio threshold. If all of the above conditions are met, the second stiffness of the plate can be used as the target steel box girder stiffness; if any of the above conditions is not met, the condition can be adjusted to meet the target stiffness. The corresponding parameters are adjusted until they meet the design requirements. Specifically, if the second normal stress is greater than the preset second normal stress threshold, the stress can be dispersed by increasing the structural cross-section to reduce the normal stress; if the first shear stress is greater than the preset first shear stress threshold, the shear force can be dispersed by increasing the cross-section to reduce the shear stress; if the stiffness of the first stiffening rib is less than the preset first stiffening rib stiffness threshold, the stiffness can be improved by increasing the cross-section of the stiffening rib; if the ratio of the first stiffening rib spacing to the first stiffened plate thickness is greater than the preset first ratio threshold, the density of the stiffening ribs can be increased by reducing the stiffening rib spacing to improve the stability of the plate.

[0105] It can be understood that for each plate connecting the crossbeam, it is necessary to check whether its corresponding third normal stress is ≤ the preset third normal stress threshold (i.e., the third allowable normal stress), whether the second shear stress is ≤ the preset second shear stress threshold (i.e., the second allowable shear stress), whether the stiffness of the second stiffening rib is ≥ the preset second stiffening rib stiffness threshold, and whether the ratio between the second stiffening rib spacing and the second stiffened plate thickness is ≤ the preset second ratio threshold. If all of the above conditions are met, the third stiffness of the plate can be used as the target connecting crossbeam stiffness; if any of the above conditions is not met, the condition can be adjusted to meet the requirements. The corresponding parameters are adjusted until the parameters meet the design requirements. Specifically, if the third normal stress is greater than the preset third normal stress threshold, the stress can be dispersed by increasing the structural cross-section to reduce the normal stress; if the second shear stress is greater than the preset second shear stress threshold, the shear force can be dispersed by increasing the cross-section to reduce the shear stress; if the stiffness of the second stiffening rib is less than the preset second stiffening rib stiffness threshold, the stiffness can be improved by increasing the cross-section of the stiffening rib; if the ratio of the second stiffening rib spacing to the second stiffened plate thickness is greater than the preset second ratio threshold, the density of the stiffening ribs can be increased by reducing the stiffening rib spacing to improve the stability of the plate.

[0106] It should be understood that after determining the target stiffness of each structure (i.e., target steel truss stiffness, target steel box girder stiffness, target connecting beam stiffness), the steel truss, steel box girder and connecting beam can be modeled as discrete units through the finite element analysis method, and the stiffness matrix of each structural component can be defined according to its geometric characteristics, material properties and boundary conditions; then the overall stiffness matrix of the box truss composite beam system is established, and the stiffness matrices of each part are merged according to the appropriate connection method, considering the mechanical behavior of the nodes and connections; the finite element analysis of the structure is carried out in combination with the external load conditions to solve the deformation, stress and other responses, and then the results obtained by comparative analysis are verified and adjusted with the target stiffness, and finally the finite element model of the target box truss composite steel beam is obtained, ensuring that the box truss composite steel beam can meet the design requirements in actual application.

[0107] In a second aspect, an embodiment of the present application further provides a box truss composite steel beam design system.

[0108] In one embodiment, referring to Figure 5 , Figure 5 This is a functional module diagram of an embodiment of the box truss composite steel beam design system of this application. Figure 5 As shown in the figure, the box truss composite steel beam design system includes:

[0109] A first processing module is configured to determine a target main beam stiffness corresponding to a preset first bridge finite element model based on the span, vertical deflection, and lateral deflection of the target bridge;

[0110] a second processing module, which is used to construct a second bridge finite element model based on the target main beam stiffness, and determine target bridge parameters based on the second bridge finite element model, a preset steel truss girder elevation, a preset steel box girder elevation, a preset first road surface minimum width, a preset second road surface minimum width, and a preset transverse spacing between the steel box girder and the steel truss girder, the target bridge parameters including a target girder height and a target girder width corresponding to the steel truss girder, a first target beam height and a first target beam width corresponding to the steel box girder, and a second target beam height and a second target beam width corresponding to a connecting crossbeam, the connecting crossbeam being used to connect the steel truss girder and the steel box girder;

[0111] The third processing module is used to construct a third bridge finite element model based on the target bridge parameters, and determine the target combined steel beam finite element model based on the third bridge finite element model, the normal stress and fatigue stress amplitude corresponding to the steel truss beam, and the normal stress, shear stress, stiffening rib stiffness, stiffening rib spacing, and stiffened rib plate thickness corresponding to the steel box beam and the connecting crossbeam respectively.

[0112] Furthermore, in one embodiment, the first processing module is specifically configured to:

[0113] Taking the quotient of the vertical deflection and the span to obtain a vertical deflection ratio;

[0114] Taking the quotient of the lateral deflection and the span to obtain a lateral deflection ratio;

[0115] If the vertical deflection ratio is not greater than a preset vertical deflection ratio threshold and the lateral deflection ratio is not greater than a preset lateral deflection ratio threshold, the first main beam stiffness is used as the target main beam stiffness.

[0116] Furthermore, in one embodiment, the first processing module is further configured to:

[0117] If the vertical deflection ratio is greater than the preset vertical deflection ratio threshold, the Y-direction moment of inertia is increased until the vertical deflection ratio is no greater than the preset vertical deflection ratio threshold, and the main beam stiffness corresponding to the increased Y-direction moment of inertia is used as the target main beam stiffness;

[0118] If the lateral deflection ratio is greater than the preset lateral deflection ratio threshold, the Z-direction moment of inertia is increased until the lateral deflection ratio is no greater than the preset lateral deflection ratio threshold, and the main beam stiffness corresponding to the increased Z-direction moment of inertia is used as the target main beam stiffness.

[0119] Furthermore, in one embodiment, the second processing module is specifically configured to:

[0120] Determining first bridge parameters based on the target main beam stiffness, the first bridge parameters including a first truss height and a first truss width corresponding to the steel truss beam, a first beam height and a first beam width corresponding to the steel box beam, and a second beam height and a second beam width corresponding to the connecting crossbeam;

[0121] A second bridge finite element model is constructed based on the first bridge parameters.

[0122] Furthermore, in one embodiment, the second processing module is further configured to:

[0123] If the difference between the first truss height and the first beam height is equal to the difference between the steel truss elevation and the steel box beam elevation, the first truss width is not less than the minimum width of the first road surface, the first beam width is not less than the minimum width of the second road surface, the lateral spacing between the steel box beam and the steel truss beam is greater than the preset lateral spacing of the tower bridge, the vertical deflection ratio is not greater than the preset vertical deflection ratio threshold, the lateral deflection ratio is not greater than the preset lateral deflection ratio threshold, and the normal stress of each component of the combined steel beam is not greater than the preset normal stress threshold, then the first bridge parameter is used as the target bridge parameter, and the combined steel beam includes a steel box beam, a steel truss beam, and a connecting crossbeam.

[0124] Furthermore, in one embodiment, the third processing module is specifically configured to:

[0125] Calculating a first stiffness corresponding to the steel truss girder, a second stiffness corresponding to the steel box girder, and a third stiffness corresponding to the connecting beam based on the target bridge parameters;

[0126] constructing a third bridge finite element model based on the first stiffness, the second stiffness, the third stiffness, and target bridge parameters;

[0127] The steel truss in the finite element model of the third bridge is simulated as a beam element, wherein the upper and lower chords of the steel truss are box-shaped and the web is I-shaped;

[0128] The steel box girder and the connecting cross beam in the third bridge finite element model are simulated according to the plate element, and the stiffening rib type of the steel box girder and the connecting cross beam is longitudinal stiffening rib or transverse stiffening rib.

[0129] Furthermore, in one embodiment, the third processing module is further configured to:

[0130] For each member of the steel truss girder, if the first normal stress corresponding to the steel truss girder is not greater than a preset first normal stress threshold, the first normal stress is less than a preset reduced stress value, and the fatigue stress amplitude is not greater than a preset fatigue stress amplitude threshold, then the first stiffness is used as the target steel truss girder stiffness;

[0131] For each plate member of the steel box girder, if the second normal stress corresponding to the steel box girder is not greater than a preset second normal stress threshold, the first shear stress corresponding to the steel box girder is not greater than a preset first shear stress threshold, the first stiffening rib stiffness corresponding to the steel box girder is not less than a preset first stiffening rib stiffness threshold, and the ratio of the first stiffening rib spacing corresponding to the steel box girder to the thickness of the first stiffened plate is not greater than a preset first ratio threshold, then the second stiffness is used as the target steel box girder stiffness;

[0132] For each plate member of the connecting beam, if the third normal stress corresponding to the connecting beam is not greater than a preset third normal stress threshold, the second shear stress corresponding to the connecting beam is not greater than a preset second shear stress threshold, the second stiffening rib stiffness corresponding to the connecting beam is not less than a preset second stiffening rib stiffness threshold, and the ratio of the second stiffening rib spacing corresponding to the connecting beam to the thickness of the second stiffened plate is not greater than a preset second ratio threshold, then the third stiffness is used as the target connecting beam stiffness;

[0133] The target composite steel beam finite element model is constructed based on the target steel truss stiffness, target steel box beam stiffness and target connecting beam stiffness.

[0134] The present application determines the target main beam stiffness corresponding to a preset first bridge finite element model based on the span, vertical deflection, and lateral deflection of the target bridge; constructs a second bridge finite element model based on the target main beam stiffness, and determines target bridge parameters based on the second bridge finite element model, a preset steel truss elevation, a preset steel box girder elevation, a preset first minimum road surface width, a preset second minimum road surface width, and a preset lateral spacing between the steel box girder and the steel truss girder, wherein the target bridge parameters include a target truss height and target truss width corresponding to the steel truss girder, a first target beam height and a first target beam width corresponding to the steel box girder, and a second target beam height and a second target beam width corresponding to the connecting beam, wherein the connecting beam is used to connect the steel truss girder and the steel box girder; constructs a third bridge finite element model based on the target bridge parameters, and determines a target combined steel beam finite element model based on the third bridge finite element model, the normal stress and fatigue stress amplitude corresponding to the steel truss girder, and the normal stress, shear stress, stiffening rib stiffness, stiffening rib spacing, and stiffened rib plate thickness corresponding to the steel box girder and the connecting beam, respectively. This application optimizes the performance of the bridge through simulation analysis without the need for extensive physical testing or repeated calculations, which not only improves computational efficiency but also reduces design and time costs.

[0135] Among them, the functional implementation of each module in the above-mentioned box-truss composite steel beam design system corresponds to the various steps in the above-mentioned box-truss composite steel beam design method embodiment, and its functions and implementation processes will not be repeated here one by one.

[0136] In a third aspect, an embodiment of the present application provides a box girder composite steel beam design device, which may be a personal computer (PC), a laptop computer, a server, or other device with data processing capabilities.

[0137] Reference Figure 6 , Figure 6 Schematic diagram of the hardware structure of the box girder composite steel beam design device involved in the embodiment of the present application. In the embodiment of the present application, the box girder composite steel beam design device may include a processor, a memory, a communication interface and a communication bus.

[0138] The communication bus may be of any type and is used to interconnect the processor, memory, and communication interface.

[0139] Communication interfaces include input / output (I / O), physical, and logical interfaces, which interconnect components within the box-truss composite steel girder design system and other devices (such as other computing devices or user devices). Physical interfaces can include Ethernet, fiber optic, and ATM interfaces; user devices can include displays and keyboards.

[0140] The memory can be various types of storage media, such as random access memory (RAM), read-only memory (ROM), non-volatile RAM (NVRAM), flash memory, optical storage, hard disk, programmable ROM (PROM), erasable PROM (EPROM), electrically erasable PROM (EEPROM), etc.

[0141] The processor may be a general-purpose processor that can invoke a box-truss composite steel beam design program stored in a memory and execute the box-truss composite steel beam design method provided in the embodiments of the present application. For example, the general-purpose processor may be a central processing unit (CPU). The methods executed when the box-truss composite steel beam design program is invoked can be referenced from the various embodiments of the box-truss composite steel beam design method of the present application and will not be further described here.

[0142] Those skilled in the art will understand that Figure 6The hardware structure shown in the figure does not constitute a limitation to the present application and may include more or fewer components than shown in the figure, or a combination of certain components, or a different arrangement of components.

[0143] In a fourth aspect, an embodiment of the present application also provides a readable storage medium.

[0144] The readable storage medium of the present application stores a box truss composite steel beam design program, wherein when the box truss composite steel beam design program is executed by a processor, the steps of the box truss composite steel beam design method as described above are implemented.

[0145] Among them, the method implemented when the box-truss composite steel beam design program is executed can refer to the various embodiments of the box-truss composite steel beam design method of this application, and will not be repeated here.

[0146] The terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned drawings are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not limited to the listed steps or units, but optionally includes steps or units that are not listed, or optionally includes other steps or units inherent to these processes, methods, products or devices. The terms "first", "second" and "third" are used to distinguish different objects, etc., and do not represent a sequence, nor do they limit the "first", "second" and "third" to different types.

[0147] In the description of the embodiments of this application, the words "exemplary," "for example," or "for example" are used to indicate examples, illustrations, or descriptions. Any embodiment or design described as "exemplary," "for example," or "for example" in the embodiments of this application should not be construed as being preferred or advantageous over other embodiments or designs. Rather, the use of words such as "exemplary," "for example," or "for example" is intended to present the relevant concepts in a concrete manner.

[0148] In the description of the embodiments of the present application, unless otherwise specified, “ / ” means or, for example, A / B can mean A or B; “and / or” in the text is merely a description of the association relationship of associated objects, indicating that three relationships may exist, for example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. In addition, in the description of the embodiments of the present application, “multiple” refers to two or more than two.

[0149] In some processes described in the embodiments of the present application, multiple operations or steps are included that appear in a specific order. However, it should be understood that these operations or steps may not be performed in the order in which they appear in the embodiments of the present application or may be performed in parallel. The sequence numbers of the operations are only used to distinguish between different operations, and the sequence numbers themselves do not represent any order of execution. In addition, these processes may include more or fewer operations, and these operations or steps may be performed in sequence or in parallel, and these operations or steps may be combined.

[0150] It should be noted that the serial numbers of the above-mentioned embodiments of the present application are for description only and do not represent the advantages or disadvantages of the embodiments.

[0151] Through the description of the above embodiments, those skilled in the art can clearly understand that the above-mentioned embodiment methods can be implemented by means of software plus the necessary general hardware platform. Of course, they can also be implemented by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of this application, or the part that contributes to the existing technology, can be embodied in the form of a software product. This computer software product is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk) as described above and includes a number of instructions for enabling a terminal device to execute the methods described in each embodiment of this application.

[0152] The above are only preferred embodiments of the present application and do not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A method for designing a box truss composite steel beam, characterized in that: The box truss composite steel beam design method includes: Determining a target main beam stiffness corresponding to a preset first bridge finite element model based on the span, vertical deflection, and lateral deflection of the target bridge; constructing a second bridge finite element model based on the target main beam stiffness, and determining target bridge parameters based on the second bridge finite element model, a preset steel truss girder elevation, a preset steel box girder elevation, a preset first road surface minimum width, a preset second road surface minimum width, and a preset transverse spacing between the steel box girder and the steel truss girder, the target bridge parameters including a target girder height and a target girder width corresponding to the steel truss girder, a first target beam height and a first target beam width corresponding to the steel box girder, and a second target beam height and a second target beam width corresponding to a connecting crossbeam, the connecting crossbeam being used to connect the steel truss girder and the steel box girder; constructing a third bridge finite element model based on the target bridge parameters, and determining a target composite steel beam finite element model based on the third bridge finite element model, the normal stress and fatigue stress amplitude corresponding to the steel truss girder, and the normal stress, shear stress, stiffening rib stiffness, stiffening rib spacing, and stiffened rib plate thickness corresponding to the steel box girder and the connecting crossbeam, respectively; The first bridge finite element model includes a preset first main beam stiffness, and determining the target main beam stiffness corresponding to the first bridge finite element model based on the span, vertical deflection, and lateral deflection of the target bridge includes: Taking the quotient of the vertical deflection and the span to obtain a vertical deflection ratio; Taking the quotient of the lateral deflection and the span to obtain a lateral deflection ratio; If the vertical deflection ratio is not greater than a preset vertical deflection ratio threshold and the lateral deflection ratio is not greater than a preset lateral deflection ratio threshold, the first main beam stiffness is used as the target main beam stiffness.

2. The box truss composite steel beam design method according to claim 1, characterized in that: The first main beam stiffness includes X-direction moment of inertia, Y-direction moment of inertia, and Z-direction moment of inertia. After the step of performing a quotient processing on the lateral deflection and the span to obtain the lateral deflection ratio, the method further includes: If the vertical deflection ratio is greater than the preset vertical deflection ratio threshold, the Y-direction moment of inertia is increased until the vertical deflection ratio is no greater than the preset vertical deflection ratio threshold, and the main beam stiffness corresponding to the increased Y-direction moment of inertia is used as the target main beam stiffness; If the lateral deflection ratio is greater than the preset lateral deflection ratio threshold, the Z-direction moment of inertia is increased until the lateral deflection ratio is no greater than the preset lateral deflection ratio threshold, and the main beam stiffness corresponding to the increased Z-direction moment of inertia is used as the target main beam stiffness.

3. The box truss composite steel beam design method according to claim 1 or 2, characterized in that: The constructing of the second bridge finite element model based on the target main beam stiffness includes: Determining first bridge parameters based on the target main beam stiffness, the first bridge parameters including a first truss height and a first truss width corresponding to the steel truss beam, a first beam height and a first beam width corresponding to the steel box beam, and a second beam height and a second beam width corresponding to the connecting crossbeam; A second bridge finite element model is constructed based on the first bridge parameters.

4. The box truss composite steel beam design method according to claim 3, characterized in that: The target bridge parameters are determined based on the second bridge finite element model, a preset steel truss girder elevation, a preset steel box girder elevation, a preset first road surface minimum width, a preset second road surface minimum width, and a preset transverse spacing between the steel box girder and the steel truss girder, including: If the difference between the first truss height and the first beam height is equal to the difference between the steel truss elevation and the steel box beam elevation, the first truss width is not less than the minimum width of the first road surface, the first beam width is not less than the minimum width of the second road surface, the lateral spacing between the steel box beam and the steel truss beam is greater than the preset lateral spacing of the tower bridge, the vertical deflection ratio is not greater than the preset vertical deflection ratio threshold, the lateral deflection ratio is not greater than the preset lateral deflection ratio threshold, and the normal stress of each component of the combined steel beam is not greater than the preset normal stress threshold, then the first bridge parameter is used as the target bridge parameter, and the combined steel beam includes a steel box beam, a steel truss beam, and a connecting crossbeam.

5. The box truss composite steel beam design method according to claim 1, characterized in that: The constructing of a third bridge finite element model based on the target bridge parameters includes: Calculating a first stiffness corresponding to the steel truss girder, a second stiffness corresponding to the steel box girder, and a third stiffness corresponding to the connecting beam based on the target bridge parameters; constructing a third bridge finite element model based on the first stiffness, the second stiffness, the third stiffness, and target bridge parameters; The steel truss in the finite element model of the third bridge is simulated as a beam element, wherein the upper and lower chords of the steel truss are box-shaped and the web is I-shaped; The steel box girder and the connecting cross beam in the third bridge finite element model are simulated according to the plate element, and the stiffening rib type of the steel box girder and the connecting cross beam is longitudinal stiffening rib or transverse stiffening rib.

6. The box truss composite steel beam design method according to claim 5, characterized in that: The target composite steel beam finite element model is determined based on the third bridge finite element model, the normal stress and fatigue stress amplitude corresponding to the steel truss beam, and the normal stress, shear stress, stiffening rib stiffness, stiffening rib spacing, and stiffened rib plate thickness corresponding to the steel box beam and the connecting crossbeam, including: For each member of the steel truss girder, if the first normal stress corresponding to the steel truss girder is not greater than a preset first normal stress threshold, the first normal stress is less than a preset reduced stress value, and the fatigue stress amplitude is not greater than a preset fatigue stress amplitude threshold, then the first stiffness is used as the target steel truss girder stiffness; For each plate member of the steel box girder, if the second normal stress corresponding to the steel box girder is not greater than a preset second normal stress threshold, the first shear stress corresponding to the steel box girder is not greater than a preset first shear stress threshold, the first stiffening rib stiffness corresponding to the steel box girder is not less than a preset first stiffening rib stiffness threshold, and the ratio of the first stiffening rib spacing corresponding to the steel box girder to the thickness of the first stiffened plate is not greater than a preset first ratio threshold, then the second stiffness is used as the target steel box girder stiffness; For each plate member of the connecting beam, if the third normal stress corresponding to the connecting beam is not greater than a preset third normal stress threshold, the second shear stress corresponding to the connecting beam is not greater than a preset second shear stress threshold, the second stiffening rib stiffness corresponding to the connecting beam is not less than a preset second stiffening rib stiffness threshold, and the ratio of the second stiffening rib spacing corresponding to the connecting beam to the thickness of the second stiffened plate is not greater than a preset second ratio threshold, then the third stiffness is used as the target connecting beam stiffness; The target composite steel beam finite element model is constructed based on the target steel truss stiffness, target steel box beam stiffness and target connecting beam stiffness.

7. A box truss composite steel beam design system, characterized in that: The box truss composite steel beam design system includes: A first processing module is configured to determine a target main beam stiffness corresponding to a preset first bridge finite element model based on the span, vertical deflection, and lateral deflection of the target bridge; a second processing module, which is used to construct a second bridge finite element model based on the target main beam stiffness, and determine target bridge parameters based on the second bridge finite element model, a preset steel truss girder elevation, a preset steel box girder elevation, a preset first road surface minimum width, a preset second road surface minimum width, and a preset transverse spacing between the steel box girder and the steel truss girder, the target bridge parameters including a target girder height and a target girder width corresponding to the steel truss girder, a first target beam height and a first target beam width corresponding to the steel box girder, and a second target beam height and a second target beam width corresponding to a connecting crossbeam, the connecting crossbeam being used to connect the steel truss girder and the steel box girder; a third processing module, configured to construct a third bridge finite element model based on the target bridge parameters, and determine a target composite steel beam finite element model based on the third bridge finite element model, the normal stress and fatigue stress amplitude corresponding to the steel truss girder, and the normal stress, shear stress, stiffening rib stiffness, stiffening rib spacing, and stiffened rib plate thickness corresponding to the steel box girder and the connecting crossbeam, respectively; The first bridge finite element model includes a preset first main beam stiffness, and the first processing module is further configured to: Taking the quotient of the vertical deflection and the span to obtain a vertical deflection ratio; Taking the quotient of the lateral deflection and the span to obtain a lateral deflection ratio; If the vertical deflection ratio is not greater than a preset vertical deflection ratio threshold and the lateral deflection ratio is not greater than a preset lateral deflection ratio threshold, the first main beam stiffness is used as the target main beam stiffness.

8. A box girder composite steel beam design device, characterized in that: The box girder composite steel beam design device includes a processor, a memory, and a box girder composite steel beam design program stored in the memory and executable by the processor, wherein when the box girder composite steel beam design program is executed by the processor, the steps of the box girder composite steel beam design method according to any one of claims 1 to 6 are implemented.

9. A computer-readable storage medium, characterized in that The computer-readable storage medium stores a box-truss composite steel beam design program, wherein when the box-truss composite steel beam design program is executed by a processor, the steps of the box-truss composite steel beam design method according to any one of claims 1 to 6 are implemented.

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