Automatic design method for transverse diaphragm of variable cross-section uhp-steel composite beam bridge

Abstract

The application discloses a variable cross-section UHPC-steel composite beam bridge diaphragm automatic design method, comprising: constructing a finite element model of a target composite beam bridge; loading a partial load lane load and a constraint condition for the finite element model and performing calculation to obtain full-bridge equivalent distortion normal stress; selecting a plurality of diaphragm units of the diaphragm with the smallest influence on the full-bridge equivalent distortion normal stress to be hidden in the finite element model; repeatedly calculating to obtain the full-bridge equivalent distortion normal stress and hiding the corresponding diaphragm units until the total amount of the remaining units of the diaphragm units meets a design volume; and taking the diaphragm form at this time as the final diaphragm form of the target composite beam bridge. In the case of determining the diaphragm arrangement spacing and material performance, the application sets the minimization of the warping normal stress as the target, performs automatic design under the limitation of a certain diaphragm material volume, and realizes the maximization of reducing the distortion effect of the bridge, and gives consideration to energy saving, material reduction and structural performance.

Description

Technical Field

[0001] This invention relates to the field of intelligent design technology, specifically to an automated design method for diaphragms of variable cross-section UHPC-steel composite beam bridges. Background Technology

[0002] In box girder bridge structures, eccentric loading can cause distortion effects, generating distorted warping normal stresses on the cross-section, which can harm the structure. Diaphragms can increase the overall structural integrity and significantly reduce the distortion effect. UHPC-steel composite girder bridges, as a new type of bridge, have not yet been widely adopted. Due to the coupling effect between the upper and lower box girders during the stress process, their deformation is quite complex, increasing the design difficulty of the upper and lower box girder diaphragms, especially in UHPC-steel composite girder bridges with variable cross-sections. Traditional diaphragm construction often follows empirical design methods, making it difficult to comprehensively consider the impact of the coupling effect between the upper and lower box girder diaphragms on the overall deformation.

[0003] Existing technologies include various documents on bridge design, such as Chinese Patent Application No. 202410639361.4, which discloses an automated selection and design method for bridge span main girder layout based on ant colony algorithm. The method includes: filtering control points based on control point information to determine main control points; determining ant colony parameters based on the main control points and a girder type library; processing the main control points for girder layout using the ant colony algorithm to generate a main girder layout strategy, with the ant colony algorithm employing the ant colony parameters; obtaining the total distance of the main girder corresponding to the main girder layout strategy; selecting a target main girder layout strategy from the main girder layout strategies based on the total distance; adding the target main girder layout strategy to the main girder layout result list and updating the iteration count; and sorting and deduplicating the main girder layout result list when the iteration count is greater than or equal to a preset iteration threshold to obtain the target main girder layout result list. While this method can automate bridge design, it becomes unsuitable when the coupling effect of upper and lower box girders is incorporated. Summary of the Invention

[0004] In order to at least overcome the above-mentioned shortcomings in the prior art, the purpose of this application is to provide an automated design method for the diaphragm of a variable cross-section UHPC-steel composite beam bridge.

[0005] In a first aspect, embodiments of this application provide an automated design method for the transverse diaphragm of a variable cross-section UHPC-steel composite beam bridge, including:

[0006] A finite element model of the target composite beam bridge is constructed, and the diaphragms in the finite element model are arranged in a fully enclosed manner.

[0007] The finite element model is loaded with off-center lane loads and constraints, and the equivalent distortion normal stress of the entire bridge is calculated.

[0008] Multiple diaphragm elements that have the least impact on the equivalent distortion normal stress of the full bridge are selected and hidden in the finite element model;

[0009] Repeated calculations are performed to obtain the equivalent distortion normal stress of the full bridge and the corresponding transverse diaphragm unit is hidden until the total number of remaining transverse diaphragm units meets the design volume.

[0010] The current diaphragm shape is taken as the final diaphragm shape of the target composite beam bridge.

[0011] In one possible implementation, calculating the equivalent distortion normal stress of the full bridge includes:

[0012] Obtain the distortion normal stress of multiple sections in the finite element model calculation results, and sum all the distortion normal stresses by norm to form the equivalent distortion normal stress of the full bridge.

[0013] In one possible implementation, the equivalent distortion normal stress of the full bridge is calculated according to the following formula:

[0014]

[0015]

[0016] In the formula, s n The equivalent distortion normal stress of the entire bridge, s s,i denoted as , where is the distorted normal stress at the i-th cross section; p is the stress norm parameter; and m is the number of cross sections. s z1,i Let be the longitudinal normal stress of the element at one corner of the bottom plate of the box girder at the i-th section; s z2,i Let be the longitudinal normal stress of the element at the other side corner of the bottom plate of the box girder at the i-th section.

[0017] In one possible implementation, the influence analysis of the diaphragm unit on the equivalent distortion normal stress of the full bridge includes:

[0018] Design variables are constructed for each of the diaphragm units, and the initial value of the design variables is 1;

[0019] Before each round of finite element calculation begins, the design variable is multiplied by the material stiffness of the diaphragm unit to obtain the stiffness of the diaphragm unit in this round of finite element calculation.

[0020] When completing a round of finite element calculation, the partial derivative of the equivalent distortion normal stress of the full bridge with respect to the design variable is calculated; the smaller the partial derivative, the smaller the influence of the diaphragm element corresponding to the design variable on the equivalent distortion normal stress of the full bridge.

[0021] In one possible implementation, the partial derivative is calculated according to the following formula:

[0022]

[0023]

[0024]

[0025] In the formula, s n The equivalent distortion normal stress of the entire bridge; p is the stress norm parameter; x j For the design variables of the j-th unit; u j Let be the element displacement matrix of the j-th element; l j Let be the element adjoint coefficient of the j-th element; k j Let be the element material stiffness of the j-th element; D 0 Here is the stiffness matrix of the element material; B j dΩ is the element displacement-strain matrix of the j-th element; j For each volume element, K is the global stiffness matrix; s s,i Let be the distorted normal stress of the i-th section; B 1,i The i-th section is only related to the longitudinal stress of the bridge. s z1,i The displacement-strain matrix corresponding to the corner elements of the base plate; B 2,i The i-th section is only related to the longitudinal stress of the bridge. s z2,i The displacement-strain matrix corresponding to the corner elements of the base plate; L 1,i The i-th section is only related to the longitudinal stress of the bridge. s z1,i The displacement transformation matrix corresponding to the corner elements of the base plate; L 2,i The i-th section is only related to the longitudinal stress of the bridge. s z2,i The displacement transformation matrix corresponding to the corner elements of the base plate; s z1,i Let be the longitudinal normal stress of the element at one corner of the bottom plate of the box girder at the i-th section; s z2,i Let be the longitudinal normal stress of the element at the other side corner of the bottom plate of the box girder at the i-th section.

[0026] In one possible implementation, hiding the diaphragm unit within the finite element model includes:

[0027] Select the diaphragm unit corresponding to the design variable with the largest partial derivative as the unit to be hidden;

[0028] Set the design variable corresponding to the unit to be hidden to 0.

[0029] In one possible implementation, the number of diaphragm units that need to be hidden in each round can be selected as follows:

[0030] The volume of the fully enclosed diaphragm is obtained as the full volume;

[0031] Calculate the difference between the full volume and the design volume, and divide the difference by the expected number of finite element calculation rounds to form the total volume of the hidden diaphragm unit in each round;

[0032] The number of diaphragm units that need to be hidden in each round is determined based on the total volume and the volume of the diaphragm unit.

[0033] In one possible implementation, determining the number of diaphragm units to be hidden per round based on the total volume and the volume of the diaphragm unit includes:

[0034] Calculate the ratio of the total volume to the average volume of the diaphragm unit and round it to determine the number of diaphragm units that the wheel needs to hide;

[0035] or;

[0036] Select multiple diaphragm units that have the least impact on the equivalent distortion normal stress of the full bridge, until the sum of the volumes of the selected diaphragm units is closest to the total volume. The number of selected diaphragm units is taken as the number of diaphragm units that need to be hidden for this wheel.

[0037] Secondly, embodiments of this application also disclose an automated design system for the transverse diaphragm of a variable cross-section UHPC-steel composite beam bridge, including:

[0038] The modeling unit is configured to construct a finite element model of the target composite beam bridge, and the diaphragms in the finite element model are arranged in a fully enclosed diaphragm configuration.

[0039] The calculation unit is configured to load the off-center lane load and constraints onto the finite element model and calculate the equivalent distortion normal stress of the entire bridge.

[0040] Hidden elements are configured to select multiple diaphragm elements that have the least impact on the equivalent distortion normal stress of the full bridge and hide them within the finite element model;

[0041] The cyclic unit is configured to repeatedly calculate and obtain the equivalent distortion normal stress of the full bridge and hide the corresponding diaphragm unit until the total number of remaining diaphragm units meets the design volume.

[0042] The design unit is configured to use the diaphragm shape at this time as the final diaphragm shape of the target composite beam bridge.

[0043] In one possible implementation, the hidden unit is further configured as follows:

[0044] Design variables are constructed for each of the diaphragm units, and the initial value of the design variables is 1;

[0045] Before each round of finite element calculation begins, the design variable is multiplied by the material stiffness of the diaphragm unit to obtain the stiffness of the diaphragm unit in this round of finite element calculation.

[0046] When completing a round of finite element calculation, the partial derivative of the equivalent distortion normal stress of the full bridge with respect to the design variable is calculated; the smaller the partial derivative, the smaller the influence of the diaphragm element corresponding to the design variable on the equivalent distortion normal stress of the full bridge.

[0047] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0048] This invention, under the premise of determining the spacing and material properties of the diaphragms, sets the goal of minimizing the warping normal stress and performs automated design within the constraints of a certain diaphragm material volume, thereby maximizing the reduction of bridge distortion effects while taking into account energy conservation, material reduction and structural performance. Attached Figure Description

[0049] The accompanying drawings, which are included to provide a further understanding of embodiments of the invention and form part of this application, do not constitute a limitation thereof. In the drawings:

[0050] Figure 1 This is a schematic diagram of the method steps in an embodiment of this application;

[0051] Figure 2 This is a schematic diagram of the finite element model in the initial state of an embodiment of this application;

[0052] Figure 3 This is a schematic diagram of the finite element model after iteration in the embodiment of this application.

[0053] The attached diagram shows the markings and corresponding component names:

[0054] 1-Upper box girder, 2-Original transverse diaphragm of upper box girder, 3-Lower box girder, 4-Original transverse diaphragm of lower box girder, 5-Designed transverse diaphragm of upper box girder, 6-Designed transverse diaphragm of lower box girder. Detailed Implementation

[0055] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. It should be understood that the accompanying drawings in this application are for illustrative and descriptive purposes only and are not intended to limit the scope of protection of this application. Furthermore, it should be understood that the schematic drawings are not drawn to scale. The flowcharts used in this application illustrate operations implemented according to some embodiments of this application. It should be understood that the operations in the flowcharts may not be implemented in sequence, and steps without logical contextual relationships may be reversed or implemented simultaneously. In addition, those skilled in the art, guided by the content of this application, may add one or more other operations to the flowcharts, or remove one or more operations from the flowcharts.

[0056] Furthermore, the described embodiments are merely some, not all, of the embodiments of this application. The components of the embodiments of this application described and illustrated herein can typically be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0057] Please refer to the following: Figure 1 This is a flowchart illustrating the automated design method for the transverse diaphragm of a variable cross-section UHPC-steel composite beam bridge provided in an embodiment of the present invention. Further, the automated design method for the transverse diaphragm of a variable cross-section UHPC-steel composite beam bridge may specifically include the contents described in steps S1-S5.

[0058] S1: Construct a finite element model of the target composite beam bridge, and the diaphragms in the finite element model are arranged in a fully enclosed manner;

[0059] S2: Load the off-center lane load and constraints onto the finite element model and calculate the equivalent distortion normal stress of the entire bridge.

[0060] S3: Select multiple diaphragm elements that have the least impact on the equivalent distortion normal stress of the full bridge and hide them in the finite element model;

[0061] S4: Repeatedly calculate and obtain the equivalent distortion normal stress of the full bridge and hide the corresponding transverse diaphragm unit until the total number of remaining transverse diaphragm units meets the design volume;

[0062] S5: The current diaphragm shape is taken as the final diaphragm shape of the target composite beam bridge.

[0063] When implementing this application, it is necessary to first construct a finite element model of the target composite beam bridge, which is a variable cross-section UHPC-steel composite beam bridge. Please refer to [link / reference]. Figure 2 The specific form of the finite element model is shown. This finite element model needs to include an upper box girder located above and a lower box girder located below. For locations where diaphragms should be installed, original diaphragms for the upper box girder and original diaphragms for the lower box girder are required. The original diaphragms referred to here are fully enclosed diaphragms. After obtaining the original parameters (thickness, dimensions, and material properties) of the upper box girder, its original diaphragms, the lower box girder, and its original diaphragms, element values ​​can be assigned to the finite element model. This is prior art, and this application embodiment does not impose further limitations.

[0064] In this embodiment, the load is an off-center lane load, which needs to be applied to the top of the upper box girder. The constraints require vertical constraints at the bottom of the lower box girder and horizontal constraints at the ends of the model. Furthermore, considering the configuration of bridge expansion joints, constraints and elements for these components can also be added. This embodiment does not impose further limitations. The fully configured finite element model can then be used to calculate the equivalent distortion normal stress of the entire bridge.

[0065] In this embodiment, by analyzing the stress state of the corresponding elements of the original transverse diaphragms of the upper and lower box girders, multiple elements with the least impact on the equivalent distortion normal stress of the entire bridge can be identified. In this embodiment, the optimal transverse diaphragm structure is positioned with the goal of minimizing warping normal stress. This means that under certain transverse diaphragm material volume constraints, automated design is implemented to maximize the reduction of bridge distortion effects while balancing energy conservation, material reduction, and structural performance. For transverse diaphragms, the closer they are to fully enclosed diaphragms, the stronger their constraint on the upper and lower box girders, and the smaller the corresponding distortion effect. However, fully enclosed diaphragms not only increase bridge weight but also construction costs. Therefore, transverse diaphragm design needs to be carried out with a clearly defined transverse diaphragm material volume. Based on the above reasons, in a round of finite element calculations, multiple transverse diaphragm elements with the least impact on the equivalent distortion normal stress of the entire bridge were selected. These elements contribute the least to resisting bridge distortion, and therefore, their removal has the least impact on bridge distortion changes. It should be understood that, in the embodiments of this application, the upper box girder can be a UHPC box girder or a steel beam, and the lower box girder can also be a UHPC box girder or a steel beam; this application embodiment does not impose any limitations. Furthermore, this embodiment is used only as an example. If the specific form of the bridge involves the combination of two or more different box girder structures, regardless of whether they are stacked vertically, placed horizontally, crossed, or any other placement method, they should all be within the scope of this embodiment.

[0066] In this embodiment, after removing these diaphragm units, the loading calculation can continue using the aforementioned load, and the corresponding diaphragm units can be selected and hidden again. This process can be repeated multiple times to obtain the corresponding diaphragm shape. The final processing result can be found in [reference needed]. Figure 3 . Figure 3 In this embodiment, the original transverse diaphragm of the upper box girder is transformed into the designed transverse diaphragm of the upper box girder after multiple cycles of unit removal. Similarly, the original transverse diaphragm of the lower box girder is transformed into the designed transverse diaphragm of the lower box girder after multiple cycles of unit removal. The designed transverse diaphragms of the lower and upper box girder constitute the final transverse diaphragm form. This embodiment minimizes structural warping stress, maximizes the structural efficiency of the transverse diaphragm, and avoids material waste caused by unreasonable design. It effectively achieves automated transverse diaphragm construction design, avoiding poor structural performance and inefficiency caused by extensive trial calculations in traditional experience-based design. Since the design domain includes both the upper and lower box girder transverse diaphragms, as well as variable cross-section states, it achieves synchronous automated design of the upper and lower box girder transverse diaphragms in variable cross-section UHPC-steel composite beam bridges. The coupling effect between the two is considered during the design process, achieving an optimal performance combination.

[0067] In one possible implementation, calculating the equivalent distortion normal stress of the full bridge includes:

[0068] Obtain the distortion normal stress of multiple sections in the finite element model calculation results, and sum all the distortion normal stresses by norm to form the equivalent distortion normal stress of the full bridge.

[0069] In one possible implementation, the equivalent distortion normal stress of the full bridge is calculated according to the following formula:

[0070]

[0071]

[0072] In the formula, s n The equivalent distortion normal stress of the entire bridge, s s,i denoted as , where is the distorted normal stress at the i-th cross section; p is the stress norm parameter; and m is the number of cross sections. s z1,i Let be the longitudinal normal stress of the element at one corner of the bottom plate of the box girder at the i-th section; s z2,i Let be the longitudinal normal stress of the element at the other side corner of the bottom plate of the box girder at the i-th section.

[0073] In the implementation of this application embodiment, the calculation of the equivalent distortion normal stress of the entire bridge is reflected by the stress difference between the two bottom corners of the box girder with different cross-sections. The box girder referred to here is a composite box girder structure with an overall cross-section of the target composite beam bridge; the cross-section refers to the cross section. In this embodiment, the stress norm parameter can be taken as 2, and the cross-sectional spacing can be taken as 1m.

[0074] In one possible implementation, the influence analysis of the diaphragm unit on the equivalent distortion normal stress of the full bridge includes:

[0075] Design variables are constructed for each of the diaphragm units, and the initial value of the design variables is 1;

[0076] Before each round of finite element calculation begins, the design variable is multiplied by the material stiffness of the diaphragm unit to obtain the stiffness of the diaphragm unit in this round of finite element calculation.

[0077] When completing a round of finite element calculation, the partial derivative of the equivalent distortion normal stress of the full bridge with respect to the design variable is calculated; the smaller the partial derivative, the smaller the influence of the diaphragm element corresponding to the design variable on the equivalent distortion normal stress of the full bridge.

[0078] In implementing this application's embodiments, to achieve full automation of the design, the process of hiding the diaphragm elements needs to be handled automatically. Specifically, a design variable with an initial value of 1 needs to be constructed first, and then the stiffness of each diaphragm element is controlled through this design variable to achieve the hiding of the diaphragm elements. It should be understood that, in the specific implementation, all partial derivatives can be calculated and sorted in ascending order; the diaphragm elements corresponding to the first few partial derivatives in the sorted order are the elements that need to be hidden.

[0079] In one possible implementation, the partial derivative is calculated according to the following formula:

[0080]

[0081]

[0082]

[0083] In the formula, s n The equivalent distortion normal stress of the entire bridge; p is the stress norm parameter; x j For the design variables of the j-th unit; u j Let be the element displacement matrix of the j-th element; l j Let be the element adjoint coefficient of the j-th element; k j Let be the element material stiffness of the j-th element; D 0 Here is the stiffness matrix of the element material; B j dΩ is the element displacement-strain matrix of the j-th element; j For each volume element, K is the global stiffness matrix; s s,i Let be the distorted normal stress of the i-th section; B 1,i The i-th section is only related to the longitudinal stress of the bridge. s z1,i The displacement-strain matrix corresponding to the corner elements of the base plate; B 2,i The i-th section is only related to the longitudinal stress of the bridge. s z2,i The displacement-strain matrix corresponding to the corner elements of the base plate; L 1,i The i-th section is only related to the longitudinal stress of the bridge. s z1,i The displacement transformation matrix corresponding to the corner elements of the base plate; L 2,iThe i-th section is only related to the longitudinal stress of the bridge. s z2,i The displacement transformation matrix corresponding to the corner elements of the base plate; s z1,i Let be the longitudinal normal stress of the element at one corner of the bottom plate of the box girder at the i-th section; s z2,i Let be the longitudinal normal stress of the element at the other side corner of the bottom plate of the box girder at the i-th section.

[0084] In one possible implementation, hiding the diaphragm unit within the finite element model includes:

[0085] Select the diaphragm unit corresponding to the design variable with the largest partial derivative as the unit to be hidden;

[0086] Set the design variable corresponding to the unit to be hidden to 0.

[0087] In one possible implementation, the number of diaphragm units that need to be hidden in each round can be selected as follows:

[0088] The volume of the fully enclosed diaphragm is obtained as the full volume;

[0089] Calculate the difference between the full volume and the design volume, and divide the difference by the expected number of finite element calculation rounds to form the total volume of the hidden diaphragm unit in each round;

[0090] The number of diaphragm units that need to be hidden in each round is determined based on the total volume and the volume of the diaphragm unit.

[0091] In the implementation of this application embodiment, because the volume of the diaphragm needs to be limited to meet the bridge's self-weight and cost requirements during the design process, there will be a design volume that is determined in the initial design. Although the diaphragm is divided into upper box girder diaphragms and lower box girder diaphragms, since the diaphragms are generally made of steel, the corresponding volumes can be combined to form the design volume without affecting the overall design result. The expected number of finite element calculation cycles can be selected between 50 and 100. By determining the expected number of finite element calculation cycles, the total volume of the hidden diaphragm units in each cycle can be estimated, thereby determining the number of hidden diaphragm units in each cycle.

[0092] In one possible implementation, determining the number of diaphragm units to be hidden per round based on the total volume and the volume of the diaphragm unit includes:

[0093] Calculate the ratio of the total volume to the average volume of the diaphragm unit and round it to determine the number of diaphragm units that the wheel needs to hide;

[0094] or;

[0095] Select multiple diaphragm units that have the least impact on the equivalent distortion normal stress of the full bridge, until the sum of the volumes of the selected diaphragm units is closest to the total volume. The number of selected diaphragm units is taken as the number of diaphragm units that need to be hidden for this wheel.

[0096] In implementing this application, two technical solutions are provided for controlling the number of diaphragm units that need to be hidden. One solution involves rounding down the ratio of the total volume to the average volume of the diaphragm units. The other solution involves selecting diaphragm units to be hidden according to their influence on the equivalent distortion normal stress of the entire bridge from smallest to largest, obtaining the volumes of these diaphragm units, and summing them until the sum is closest to the total volume. The first solution is suitable for situations where the diaphragm unit volumes are relatively uniform, while the second solution is suitable for all situations.

[0097] Based on the same inventive concept, embodiments of this application also disclose an automated design system for the transverse diaphragm of a variable cross-section UHPC-steel composite beam bridge, including:

[0098] The modeling unit is configured to construct a finite element model of the target composite beam bridge, and the diaphragms in the finite element model are arranged in a fully enclosed diaphragm configuration.

[0099] The calculation unit is configured to load the off-center lane load and constraints onto the finite element model and calculate the equivalent distortion normal stress of the entire bridge.

[0100] Hidden elements are configured to select multiple diaphragm elements that have the least impact on the equivalent distortion normal stress of the full bridge and hide them within the finite element model;

[0101] The cyclic unit is configured to repeatedly calculate and obtain the equivalent distortion normal stress of the full bridge and hide the corresponding diaphragm unit until the total number of remaining diaphragm units meets the design volume.

[0102] The design unit is configured to use the diaphragm shape at this time as the final diaphragm shape of the target composite beam bridge.

[0103] In one possible implementation, the hidden unit is further configured as follows:

[0104] Design variables are constructed for each of the diaphragm units, and the initial value of the design variables is 1;

[0105] Before each round of finite element calculation begins, the design variable is multiplied by the material stiffness of the diaphragm unit to obtain the stiffness of the diaphragm unit in this round of finite element calculation.

[0106] When completing a round of finite element calculation, the partial derivative of the equivalent distortion normal stress of the full bridge with respect to the design variable is calculated; the smaller the partial derivative, the smaller the influence of the diaphragm element corresponding to the design variable on the equivalent distortion normal stress of the full bridge.

[0107] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of both. To clearly illustrate the interchangeability of hardware and software, the components and steps of the various examples have been generally described in terms of functionality in the foregoing description. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementations should not be considered beyond the scope of this invention.

[0108] In the several embodiments provided in this application, it should be understood that the disclosed apparatus and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative. For instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. In addition, the mutual coupling or direct coupling or communication connection shown or discussed may be indirect coupling or communication connection through some interfaces, devices or units, or may be electrical, mechanical or other forms of connection.

[0109] The units described as separate components may or may not be physically separate. As will be apparent to those skilled in the art, the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of both. To clearly illustrate the interchangeability of hardware and software, the components and steps of the various examples have been generally described in terms of functionality in the foregoing description. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementations should not be considered beyond the scope of this invention.

[0110] Furthermore, the functional units in the various embodiments of the present invention can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0111] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or grid device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0112] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. An automated design method for diaphragms of variable cross-section UHPC-steel composite beam bridges, characterized in that, include: A finite element model of the target composite beam bridge is constructed, and the diaphragms in the finite element model are arranged in a fully enclosed manner. The finite element model is loaded with off-center lane loads and constraints, and the equivalent distortion normal stress of the entire bridge is calculated. Multiple diaphragm elements that have the least impact on the equivalent distortion normal stress of the full bridge are selected and hidden in the finite element model; Repeated calculations are performed to obtain the equivalent distortion normal stress of the full bridge and the corresponding transverse diaphragm unit is hidden until the total number of remaining transverse diaphragm units meets the design volume. The current diaphragm shape is taken as the final diaphragm shape of the target composite beam bridge. The influence analysis of the transverse diaphragm unit on the equivalent distortion normal stress of the full bridge includes: Design variables are constructed for each of the diaphragm units, and the initial value of the design variables is 1; Before each round of finite element calculation begins, the design variable is multiplied by the material stiffness of the diaphragm unit to obtain the stiffness of the diaphragm unit in this round of finite element calculation. When completing a round of finite element calculation, the partial derivative of the equivalent distortion normal stress of the full bridge with respect to the design variable is calculated; the smaller the partial derivative, the smaller the influence of the diaphragm element corresponding to the design variable on the equivalent distortion normal stress of the full bridge. The partial derivatives are calculated according to the following formula: In the formula, σ n The equivalent distortion normal stress of the entire bridge; p is the stress norm parameter; x j For the design variables of the j-th unit; u j Let be the element displacement matrix of the j-th element; λ j Let be the element adjoint coefficient of the j-th element; k j Let be the element material stiffness of the j-th element; D 0 Here is the stiffness matrix of the element material; B j dΩ is the element displacement-strain matrix of the j-th element; j For each volume element, K is the global stiffness matrix; σ s,i Let be the distorted normal stress of the i-th section; B 1,i The i-th section is only related to the longitudinal stress of the bridge. σ z1,i The displacement-strain matrix corresponding to the corner elements of the base plate; B 2,i The i-th section is only related to the longitudinal stress of the bridge. σ z2,i The displacement-strain matrix corresponding to the corner elements of the base plate; L 1,i The i-th section is only related to the longitudinal stress of the bridge. σ z1,i The displacement transformation matrix corresponding to the corner elements of the base plate; L 2,i The i-th section is only related to the longitudinal stress of the bridge. σ z2,i The displacement transformation matrix corresponding to the corner elements of the base plate; σ z1,i Let be the longitudinal normal stress of the element at one corner of the bottom plate of the box girder at the i-th section; σ z2,i Let be the longitudinal normal stress of the element at the other side corner of the bottom plate of the box girder at the i-th section.

2. The automated design method for diaphragms of variable cross-section UHPC-steel composite beam bridges according to claim 1, characterized in that, The calculation of the equivalent distortion normal stress of the entire bridge includes: Obtain the distortion normal stress of multiple sections in the finite element model calculation results, and sum all the distortion normal stresses by norm to form the equivalent distortion normal stress of the full bridge.

3. The automated design method for the transverse diaphragm of a variable cross-section UHPC-steel composite beam bridge according to claim 2, characterized in that, The equivalent distortion normal stress of the full bridge is calculated according to the following formula: In the formula, σ n The equivalent distortion normal stress of the entire bridge, σ s,i p is the distortion normal stress of the i-th section; is the stress norm parameter; m is the number of sections; σ z1,i Let be the longitudinal normal stress of the element at one corner of the bottom plate of the box girder at the i-th section; σ z2,i Let be the longitudinal normal stress of the element at the other side corner of the bottom plate of the box girder at the i-th section.

4. The automated design method for diaphragms of variable cross-section UHPC-steel composite beam bridges according to claim 1, characterized in that, Hiding the diaphragm unit within the finite element model includes: Select the diaphragm unit corresponding to the design variable with the largest partial derivative as the unit to be hidden; Set the design variable corresponding to the unit to be hidden to 0.

5. The automated design method for diaphragms of variable cross-section UHPC-steel composite beam bridges according to claim 1, characterized in that, The selection of the number of diaphragm units that need to be hidden in each round includes: The volume of the fully enclosed diaphragm is obtained as the full volume; Calculate the difference between the full volume and the design volume, and divide the difference by the expected number of finite element calculation rounds to form the total volume of the hidden diaphragm unit in each round; The number of diaphragm units that need to be hidden in each round is determined based on the total volume and the volume of the diaphragm unit.

6. The automated design method for the transverse diaphragm of a variable cross-section UHPC-steel composite beam bridge according to claim 5, characterized in that, The number of diaphragm units that need to be hidden in each round is determined based on the total volume and the volume of the diaphragm unit, including: Calculate the ratio of the total volume to the average volume of the diaphragm unit and round it to determine the number of diaphragm units that the wheel needs to hide; or; Select multiple diaphragm units that have the least impact on the equivalent distortion normal stress of the full bridge, until the sum of the volumes of the selected diaphragm units is closest to the total volume. The number of selected diaphragm units is taken as the number of diaphragm units that need to be hidden for this wheel.

7. An automated design system for diaphragms of variable cross-section UHPC-steel composite beam bridges using the method described in any one of claims 1 to 6, characterized in that, include: The modeling unit is configured to construct a finite element model of the target composite beam bridge, and the diaphragms in the finite element model are arranged in a fully enclosed diaphragm configuration. The calculation unit is configured to load the off-center lane load and constraints onto the finite element model and calculate the equivalent distortion normal stress of the entire bridge. Hidden elements are configured to select multiple diaphragm elements that have the least impact on the equivalent distortion normal stress of the full bridge and hide them within the finite element model; The cyclic unit is configured to repeatedly calculate and obtain the equivalent distortion normal stress of the full bridge and hide the corresponding diaphragm unit until the total number of remaining diaphragm units meets the design volume. The design unit is configured to use the current diaphragm shape as the final diaphragm shape of the target composite beam bridge.

8. The automated design system for the transverse diaphragm of a variable cross-section UHPC-steel composite beam bridge according to claim 7, characterized in that, The hidden unit is also configured to: Design variables are constructed for each of the diaphragm units, and the initial value of the design variables is 1; Before each round of finite element calculation begins, the design variable is multiplied by the material stiffness of the diaphragm unit to obtain the stiffness of the diaphragm unit in this round of finite element calculation. When completing a round of finite element calculation, the partial derivative of the equivalent distortion normal stress of the full bridge with respect to the design variable is calculated; the smaller the partial derivative, the smaller the influence of the diaphragm element corresponding to the design variable on the equivalent distortion normal stress of the full bridge.

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