Method for generating a tensile and compressive strut model of a perforated box girder, computer device and medium

Abstract

The application provides a method for generating a perforated box girder tension-compression rod model, a computer device and a medium. The method comprises a structure size judgment stage, a plane or solid model establishment stage, a structure topology stage, an image optimization stage, a truss structure extraction stage, a short rod elimination and merging stage, a rod internal force calculation stage, a deviation index calculation stage, a structure optimization stage, and a bearing capacity review and steel bar configuration stage. The computer device comprises at least one processor and a memory storing program instructions, the program instructions are executed by the at least one processor, and the program instructions comprise instructions for executing the method described above. The readable storage medium stores computer program instructions, which are executed by the processor to implement the method described above. The method is simple, can avoid special topology changes of the topology optimization result in the manual generation of the tension-compression rod model, and simplifies the generation process of the STM model in engineering practice.

Description

Technical Field

[0001] This invention relates to the field of building engineering, and more specifically, to a method, computer equipment, and medium for generating a tension / compression bar model of a perforated box girder. Background Technology

[0002] Open-type box girder structures are typical reinforced concrete members in the d-zone. Their cross-sectional strain does not conform to the plane section assumption, resulting in complex stress distribution, rendering beam section theory inapplicable. The tension-compression bar model reasonably explains the stress distribution in reinforced concrete d-zone members, with a clear force transmission path and straightforward design approach, and has been applied in concrete structure design codes of some countries. However, obtaining a reasonable tension-compression bar model without manual interpretation remains a challenge in design. Summary of the Invention

[0003] The purpose of this invention is to address at least one of the aforementioned deficiencies in the prior art.

[0004] To achieve the above objectives, the present invention provides a method for generating a tension / compression bar model of a perforated box girder.

[0005] The method may include the following steps: (1) determining the structural dimensions of a given perforated box girder and classifying it as a two-dimensional or three-dimensional structure; (2) performing structural modeling for the two-dimensional or three-dimensional structure; (3) performing FEM analysis on the two-dimensional or three-dimensional structural model to obtain the structural topology; (4) deleting redundant mesh elements in the topological structure without changing the topological skeleton structure to obtain the optimization result; (5) identifying the nodes and members in the optimization result and combining them into a truss-like structure; (6) reducing the number of tie rods to obtain the optimized truss-like structure; (7) performing internal force calculation on the optimized truss-like structure to obtain the actual force on each member; (8) calculating the single tie rod deviation index based on the actual force on each member. S i and overall deviation index S And determine whether both are greater than the corresponding deviation index limit; (9) in S i and S If any of the values ​​in the equation exceeds the corresponding tension / compression bar index limit, the truss-like structure is adjusted to meet the deviation index requirement and geometric constraint requirement, thus obtaining the model described above.

[0006] In this embodiment, the method may further include step (10): verifying the structural bearing capacity of the model obtained in step (9) and obtaining the reinforcement configuration.

[0007] In this embodiment, in step (2), a planar four-point unit is used to establish a structural model for a two-dimensional structure, and a three-dimensional solid eight-node unit is used to model a three-dimensional structure.

[0008] In this embodiment, in step (4), the topology is optimized by image conversion and removal of boundary pixels. The image conversion includes converting the topology into binary data to obtain a binary image. The removal of boundary pixels includes iteratively removing the boundary pixels of the binary image.

[0009] In this embodiment, the following node determination rules and rod determination rules are followed in step (5). The node determination rules include: for two-dimensional nodes, a 3*3 grid centered on it is detected. If its average density is greater than or equal to 1 / 3, it is identified as a candidate node; load points and support points are used as candidate nodes; if the distance between two candidate nodes is less than 1.5 times the grid size, a single node is used to replace it at the average position; for three-dimensional nodes, a 3*3*3 grid centered on it is detected. If its average density is greater than or equal to 1 / 9, it is used as a node; the rod determination rules include: first, each node is directly connected by rods, and redundant rods are deleted by comparing the number of grids traversed by the connection path of the initial rods with the pixel repetition rate of the refined topological skeleton.

[0010] In this embodiment, in step (6), the number of members with smaller tension is reduced by eliminating and merging short rods. This step includes: setting a minimum short rod size limit, iteratively checking the length of all tie rods in the combined truss structure of step (5), and once the short rod size is less than the set limit, setting the center position of the short rod as the new node position and eliminating the short rod.

[0011] In this embodiment, in step (8), S i and S The deviation index limits can be 0.1 and 0.05 respectively; the following two formulas can be used to calculate the deviation index limits. S i and S :

[0012] , ,

[0013] in, N i and V i These are the axial force and shear force of the member with the corresponding number i.

[0014] In this embodiment, the adjustment method in step (9) may include: adjusting the node position, setting the fluctuation range and the distance of each fluctuation.

[0015] In another aspect, the present invention provides a computer device.

[0016] The device may include: at least one processor; and a memory storing program instructions, wherein the program instructions are configured to be executed by the at least one processor, the program instructions including instructions for performing the method as described above.

[0017] In another aspect, the present invention provides a computer-readable storage medium.

[0018] The computer-readable storage medium stores computer program instructions that, when executed by a processor, implement the method described above.

[0019] Compared with the prior art, the beneficial effects of the present invention may include at least one of the following:

[0020] (1) The method of the present invention is simple and can automatically extract the tension and compression rod results from the topology results. It can avoid the special topology changes that are common in the topology optimization results of manually generating tension and compression rod models (STM) for box girder structures, and simplify the generation process of STM models in engineering practice.

[0021] (2) Compared with the design load-bearing capacity, the present invention may achieve a higher load-bearing capacity level, ensuring the safety of the structure.

[0022] (3) Compared with traditional standard design methods, the present invention can significantly reduce the amount of steel bars used, resulting in better economic efficiency.

[0023] (4) The present invention enables high efficiency in the use of materials.

[0024] (5) The method of the present invention generates tension and compression rods quickly and efficiently.

[0025] (6) This invention has high applicability and is suitable for various types of d-zone tension and compression bar designs in 2D and 3D. Attached Figure Description

[0026] The above and other objects and / or features of the present invention will become clearer from the following description taken in conjunction with the accompanying drawings, in which:

[0027] Figure 1 A schematic flowchart of the method for generating a tension / compression bar model of a perforated box girder according to the present invention is shown.

[0028] Figure 2 A schematic diagram of the two-dimensional node determination mode of the present invention is shown.

[0029] Figure 3 A schematic diagram of the three-dimensional node determination mode of the present invention is shown.

[0030] Figure 4 The geometry, load, and boundary conditions of half of the two-dimensional perforated box girder in Example 1 of the present invention are shown.

[0031] Figure 5 The loading points and boundary conditions for the 2D box girder mesh generation are shown.

[0032] Figure 6 Example 1 of the present invention shows the topology obtained in step three.

[0033] Figure 7 The result of 2D image optimization in step four is shown in Example 1 of the present invention.

[0034] Figure 8 The truss-like structure obtained by Example 1 of the present invention is shown.

[0035] Figure 9 Example 1 of the present invention shows the tension / compression bar result and the magnitude of the internal force obtained in step nine.

[0036] Figure 10 The diagram shows the steel reinforcement arrangement obtained from the topology in Example 1 of the present invention.

[0037] Figure 11 The geometry, loading, and boundary conditions of the 1 / 4 three-dimensional perforated box girder in Example 2 of the present invention are shown.

[0038] Figure 12 The loading points and boundary conditions for the 3D box girder mesh generation are shown.

[0039] Figure 13 Example 2 of the present invention shows the topology obtained in step three.

[0040] Figure 14 Example 2 of the present invention shows the result after 3D image optimization in step four.

[0041] Figure 15 The truss-like structure obtained by Example 2 of the present invention is shown.

[0042] Figure 16 Example 2 of the present invention shows the tension / compression rod result and the magnitude of the internal force obtained in step nine.

[0043] Figure 17 Example 2 of the invention shows a steel reinforcement layout diagram obtained from the topology. Detailed Implementation

[0044] In the following sections, the method for generating the tension / compression bar model of the perforated box girder of the present invention, the computer equipment, and the medium will be described in detail with reference to exemplary embodiments.

[0045] Addressing the technical problem that existing models of tension-compression members cannot be obtained without manual interpretation, this invention proposes a method for generating tension-compression member models of perforated box girder structures based on continuum optimization. This method starts with a design problem that includes geometry, boundary conditions, and load conditions, performs topology optimization based on flexibility minimization, and employs a penalized solid isotropic material method (SIMP) to obtain an optimized material layout.

[0046] Exemplary Example 1

[0047] This exemplary embodiment provides a method for generating a tension / compression bar model of a perforated box girder.

[0048] The method may include multiple stages: structural dimension determination stage, performing two-dimensional and three-dimensional classification; planar or solid model establishment stage; structural topology stage; image optimization stage; truss-like structure extraction stage; short member elimination and merging stage; member internal force calculation stage; deviation index calculation stage; structural optimization stage; bearing capacity verification and reinforcement configuration stage. Specifically, the method includes:

[0049] S01: Structural Dimension Determination Stage

[0050] In this embodiment, the step may include: determining the structural dimensions and classifying the open box girder into a two-dimensional structure or a three-dimensional structure.

[0051] S02: Stage of Creating a Plane or Solid Model

[0052] In this embodiment, the step may include: for two-dimensional and three-dimensional structures, different meshes (planar four-node and three-dimensional solid eight-node) are required for structural modeling.

[0053] S03: Structural Topology Stage

[0054] In this embodiment, the step may include: performing FEM analysis on the structure (i.e., the model established in step S02) to obtain the structural topology.

[0055] In this embodiment, the material distribution of the perforated box girder structure can be optimized using the classic SIMP topology method. Based on the design objective of minimizing flexibility, and given the mesh size, filter radius, and volume fraction, the mathematical expression of the problem is as follows:

[0056] ,

[0057] in, C For softness, F For strength, U For displacement, K Here is the stiffness matrix. α It is the volume fraction. ρFor density, ε To set a minimum material density, V For material volume, This is the total volume.

[0058] S04: Image Optimization Stage

[0059] In this embodiment, the step may include: deleting redundant mesh cells without changing the topological skeleton, so as to make the topological structure clearer.

[0060] S05: Truss-like Structure Extraction Stage

[0061] In this embodiment, the step may include: identifying nodes and members in the refinement results and combining them into a truss-like structure.

[0062] S06: Short Rod Elimination and Merging Phase

[0063] In this embodiment, the step may include: reducing the number of tie rods by eliminating and merging shorter rods to reduce the number of tie rods.

[0064] S07: Calculation Stage of Internal Forces in Members

[0065] In this embodiment, the step may include: calculating the internal forces of the identified truss-like members, and using beam elements to perform finite element analysis on the structure.

[0066] S08: Deviation Index Calculation Stage

[0067] In this embodiment, the deviation index includes both the overall structure and individual tie rods. The tension-compression member design method requires a truss simulation model that satisfies axial force balance; however, the extracted truss-like structure is usually an unstable truss, containing not only axial forces but also shear forces and bending moments. Therefore, the obtained truss-like structure needs to be adjusted to a tension-compression member structure that meets certain constraints. This invention addresses this by defining a single tie rod deviation index. S i and overall deviation index S To actually measure the degree of axial force balance, set S i and S The limit values ​​enable the structure to achieve the aforementioned axial force balance in an effective tension / compression member model after the truss-like adjustment phase, where, S i and S Defined as:

[0068] , ,

[0069] in, N i and Vi These are the axial force and shear force of the corresponding member numbered i, and n is the number of members.

[0070] S09: Structural Optimization Stage

[0071] In this embodiment, the present invention can make structural adjustments to truss-like structures that do not meet the deviation index, while ensuring that the results always meet geometric limits, such as opening restrictions and concrete cover thickness requirements, so as to obtain a tension / compression bar model that meets the requirements.

[0072] Clearly, the entire generation method of this invention can be implemented based on a computer program, making it a complete and automated process. This method avoids the special topological changes that may occur when manually interpreting topological results and converting them into tension / compression bar structures, thus simplifying the generation process of tension / compression bar models in practical engineering.

[0073] Exemplary Example 2

[0074] This exemplary embodiment provides a method for generating a tension / compression bar model of a perforated box girder. Figure 1 A flowchart illustrating the method for generating the tension / compression bar model of the perforated box girder according to the present invention is shown. Figure 1 The method described may include the following stages:

[0075] (1) Structural Dimension Determination Stage

[0076] This step can determine the structural dimensions of a given open box girder to identify whether the structure is a two-dimensional or three-dimensional model.

[0077] (2) Plane or solid model creation stage

[0078] For a given perforated box girder structure, structural models are established using planar four-node elements or solid eight-node elements for both two-dimensional and three-dimensional models. The mesh size can be determined based on the actual structure and dimensions, or it can be determined independently; for example, a certain range of mesh sizes can be determined based on the minimum structural dimensions of the model. After the model is established, boundary conditions are defined and loads are applied, and element stiffness is calculated for subsequent topology solving.

[0079] (3) Structural Topology Stage

[0080] The selection of the filter radius and volume fraction can be determined based on the minimum structural size of the model or can be determined autonomously. The density penalty factor is set to 3, and the initial mesh density is set to 0.5. By varying the mesh density, the density arrangement that minimizes strain energy under the specified volume fraction is sought. For a two-dimensional model, the following is defined: SE For strain energy, when the variable JWhen the value is less than 0.001, it represents the final topological image; for 3D models, due to program calculation time constraints, the number of transformations can be set to 50 or the variable number can be selected depending on the urgency. J A value less than 0.001 is used to determine the final topology result. (Variable) J Defined as:

[0081] ,

[0082] in, J As variables, SE For strain energy, i Let represent the number of transformations, for example, the i-th transformation.

[0083] if J The value is small, indicating that the reduction in strain energy after transformation is minimal, therefore no further transformation is necessary.

[0084] (4) Image optimization stage

[0085] The obtained material layout topology results are transformed into 2D binary data (0 and 1). Material density limits are defined. The density of cells with a density less than the limit is set to 0, and the density of cells with a density greater than the limit is set to 1. This achieves binary data conversion and deletes grid arrangements with lower density.

[0086] Next, boundary pixel removal is performed, and the topological result is refined without changing the topological structure. The binary image is refined by iteratively removing boundary pixels and removing redundant pixels. The resulting skeleton curve is only one pixel wide, and the loading point and support position are defined as fixed pixels.

[0087] (5) Truss-like structure extraction stage

[0088] The main step in the reconstruction phase is node and member identification. In the process of identifying nodes and members, this invention proposes node determination rules and member determination rules for both two-dimensional and three-dimensional structures:

[0089] The node determination rules include: for two-dimensional structures, node detection is based on a binary skeleton. Since the obtained skeleton curve is at most one pixel wide, node determination rules are defined to identify candidate nodes by examining each pixel in the skeleton. An example of a two-dimensional node determination mode is shown below. Figure 2As shown, for 2D nodes, a 3x3 grid centered on that node is detected. If its average density is greater than or equal to 1 / 3, it is identified as a candidate node. Load points and support points are also considered as candidate nodes. Based on the node determination pattern, multiple nodes may cluster in a small area. In this case, redundant nodes are removed. If the distance between two candidate nodes is less than 1.5 times the grid size, a single node is used to replace them at the average position. An example of the 3D node determination pattern is shown below. Figure 3 As shown, for a 3D node, a 3x3x3 grid centered on it is detected. If its average density is greater than or equal to 1 / 9, it is considered a node. No such node is deleted.

[0090] The rules for determining the links include: first, connecting each node directly through the links. Since the original topological skeleton is only one pixel wide, redundant links are deleted by comparing the number of grids traversed by the connection path of the initial link with the pixel repetition rate of the refined topological skeleton. The initial number of links is n*(n-1) / 2, where n is the number of nodes. Each link is compared and deleted.

[0091] (6) Short rod elimination and merging stage

[0092] This stage only targets short tie rods. The initially generated truss-like structure can have various short tie rods. This invention proposes a merging method to eliminate these short tie rods. In this method, the minimum short rod size can be determined based on the minimum structural size of the model. The length of all tie rods in the generated truss structure is iteratively checked. Once the short rod size is less than a set limit, the center position of the short rod is set as the new node position and the short rod is eliminated.

[0093] (7) Calculation stage of internal forces of members

[0094] The internal forces of the truss-like structure in stage (6) are calculated. If the members are considered as truss structures and only bear axial forces, the members cannot be in force equilibrium. Therefore, the members use self-defined beam elements, which can bear shear forces and bending moments in addition to axial forces to transfer internal forces. It should be noted that the degrees of freedom of the members in the planar and solid models are different, so different beam elements are required. Finally, the internal forces of the members are calculated by the finite element method, that is, the axial forces of each member. N i and shear force V i .

[0095] (8) Deviation Index Calculation Stage

[0096] At this stage, the deviation index for a single lever is limited. S i Not greater than 0.1, for the overall deviation index, SNot greater than 0.05; the degree of truss-like structure is defined from two dimensions: individual member and overall structure. Substitute the member internal force value from the previous stage into the defined formula (i.e., above). S i and S The formula (defined) is used to calculate and determine whether the deviation from the exponential limit has been reached, so that structural adjustments can be made.

[0097] (9) Structural adjustment stage

[0098] The structure is adjusted according to the Si and S indices to meet the deviation index conditions. The specific adjustment method is to adjust the node positions according to the set fluctuation range and the distance of each fluctuation. At the same time, during the adjustment process, the structure is made to always meet the geometric constraints, including the thickness of the steel reinforcement protective layer and the restrictions on openings.

[0099] (10) Bearing capacity verification and reinforcement configuration stage

[0100] Since the node dimensions were adjusted from the topology to the subsequent truss-like structure, the structural bearing capacity needs to be checked. The obtained component information is imported into the finite element analysis software diana for direct structural analysis to verify whether the bearing capacity reaches the design bearing capacity and to obtain the reinforcement layout.

[0101] To better understand the exemplary embodiments of the present invention described above, further explanation is provided below with reference to specific examples.

[0102] Example 1

[0103] This example illustrates the tension / compression bar model generation method of the present invention for a two-dimensional perforated box girder. Because its structure is symmetrical, this example analyzes only half of it. The geometry, loading, and boundary conditions of this structure are as follows: Figure 4 The structure is shown to be 500 mm thick.

[0104] The generation method includes the following steps:

[0105] Step 1: The open box girder in this example is a two-dimensional model.

[0106] Step 2: Create a planar model.

[0107] The structural model is built using planar four-node elements. The mesh size can be determined based on the minimum structural dimensions of the model, or a custom-designed mesh size can be used. After the model is built, boundary conditions are defined and loads are applied, such as... Figure 5 As shown, the boundary conditions are defined and the loads are applied. The two points a and b above it are the loading positions, the point c below it is the support position, and the thick line L on the right is the boundary condition.

[0108] Step 3: 2D structure topology.

[0109] Planar elements are used to optimize the material distribution for a given problem using the SIMP topology optimization method. The topology is obtained based on a suitable volume fraction and filter radius, such as... Figure 6 As shown.

[0110] Step 4: 2D image optimization.

[0111] This step includes two steps: image conversion and boundary pixel removal.

[0112] (1) Image Conversion: The obtained results are converted into binary data. Although the TO results largely represent the empty / solid regions of the structural domain, some densities have intermediate values. Explicit binary data is needed in the second stage, so the TO results are converted into binary data by setting a threshold. To preserve the original topology in the binary data, the threshold can be set to 0.1. All densities below this value are converted to void states, and the remainder are set to solid states.

[0113] (2) Boundary pixel removal: The binary image is skeletonized by iteratively removing boundary pixels until no further pixels can be removed without changing the topological structure. During the thinning process, pixel-level elimination rules can be used to determine movable boundary pixels without altering the topological structure. The thinning result is as follows: Figure 7 As shown.

[0114] Steps five and six: Truss-like node picking and short member elimination and merging. Truss-like structures are obtained through node identification, member identification, and short member merging, such as... Figure 8 As shown, Figure 8 Each number in the table represents a node.

[0115] Step 7: Using FEM finite element analysis, the members are set as beam elements to calculate the internal forces of the structure and obtain the actual force on each member.

[0116] Step 8: Substitute the internal forces of the member into the deviation index Si and S. In this example, Si is less than 0.1 and S is 0.0699, which is greater than the limit of 0.05 for tension / compression members.

[0117] Step 9: Structural Adjustment.

[0118] The obtained results were shape optimized to meet the deviation exponential and geometric constraints. The optimized S value was 0.0049, which met the requirements. The final tension / compression member results and internal force magnitudes are as follows: Figure 9 As shown, where, Figure 9 The middle arrow indicates the direction of loading. The number 1 near the arrow is the unit force, in N. The value near the rod is the magnitude of the internal force of the rod, in N.

[0119] Step 10: Load-bearing capacity verification and reinforcement arrangement.

[0120] In this example, assuming the yield strength of the reinforcing steel is fy = 580 MPa, the obtained component information is imported into the finite element analysis software diana for direct structural analysis. This verifies that the bearing capacity reaches 1.1 times the design bearing capacity. The reinforcing steel arrangement obtained from the topology is as follows: Figure 10 As shown, the thin lines in the diagram (the lines with numbers next to them) represent steel bars, and the numbers indicate the diameter of the steel bars in mm.

[0121] Example 2

[0122] This example illustrates the tension / compression bar model generation method of the present invention for a three-dimensional perforated box girder. Because its structure is symmetrical, this example analyzes one-quarter of it. The geometry, loading, and boundary conditions of this structure are as follows: Figure 11 As shown in the figure, the Chinese meaning of "symmetry surface" is symmetry plane.

[0123] Step 1: The open box girder in this example is a three-dimensional model.

[0124] Step 2: Solid model building. A structural model is built using eight-node solid elements. The mesh size can be determined based on the minimum structural dimensions of the model. After the model is built, boundary conditions are defined and loads are applied, such as... Figure 12 As shown, a 3D box girder mesh was created, where, Figure 12 The leftmost point in the diagram represents the support position, the other points represent the loading positions, and the two faces represent the boundary conditions.

[0125] Step 3: 3D structural topology.

[0126] Solid elements are used to optimize the material distribution for a given problem using the SIMP topology optimization method. The topology is obtained based on a suitable volume fraction and filter radius, such as... Figure 13 As shown.

[0127] Step 4: 3D image optimization.

[0128] This stage includes two steps: image transformation and boundary pixel removal, specifically:

[0129] (1) Image conversion: The obtained results are converted into binary data. Although the TO results largely represent the empty / solid regions of the structural domain, some densities have intermediate values. Explicit binary data is needed in the second stage, so the TO results are converted into binary data by setting a threshold. To preserve the original topology in the binary data, the present invention sets the threshold to 0.1, and all densities below this value are converted to void states, while the remainder are set as solid.

[0130] (2) Boundary pixel removal. The binary image is skeletonized by iteratively removing boundary pixels until no further pixels can be removed without changing the topology. During the thinning process, pixel-level elimination rules are used to determine movable boundary pixels without changing the topology. The thinning result is as follows: Figure 14 As shown.

[0131] Steps five and six involve 3D truss extraction, short member elimination, and merging. Through node identification, member identification, and short member merging, a truss-like structure is obtained, such as... Figure 15 As shown, Figure 15 The numbers in the table represent the individual nodes.

[0132] Step 7: Using FEM finite element analysis, the members are set as beam elements to calculate the internal forces of the structure and obtain the actual force on each member.

[0133] Step 8: Substitute the internal forces of the member to calculate the deviation index. S i and S In this example S i All are less than 0.1, in this example. S The value is 0.2883, which is greater than the tension / compression bar index limit of 0.05.

[0134] Step 9: Structural Adjustment.

[0135] The obtained result is then shaped to meet the deviation exponential requirement and geometric constraint requirement. The optimized result is... S The value is 0.0362, which meets the requirements. The final tension / compression member results and internal force magnitudes are as follows: Figure 16 As shown in the figure, the arrows represent the direction of loading, the number 1 near the arrow represents 1 unit force, 0.5 represents 0.5 unit force, and the unit is N; the values ​​near the rods represent the magnitude of the internal force of the rods, and the unit is N.

[0136] Step 10: Load-bearing capacity verification and reinforcement arrangement.

[0137] For this example, let the yield strength of the steel reinforcement be f. y=580MPa. The obtained component information was imported into the finite element analysis software DIA for direct structural analysis, verifying that the bearing capacity reached 1.1 times the design bearing capacity. The reinforcement arrangement obtained from the topology is as follows. Figure 17 As shown in the diagram, the thick lines (lined with numbers next to them) represent reinforcing bars, and the numbers indicate the diameter of the reinforcing bars in mm.

[0138] The method for generating tension / compression bar models of the present invention can be programmed into a computer program and the corresponding program code or instructions can be stored in a computer-readable storage medium. When the program code or instructions are executed by a processor, the processor performs the above method. The processor and memory described below can be included in a computer device.

[0139] Exemplary Example 3

[0140] This exemplary embodiment provides a computer device.

[0141] The device may include: at least one processor; and a memory storing program instructions, wherein the program instructions are configured to be executed by the at least one processor, the program instructions including instructions for performing the method according to Example Embodiment 1 or 2.

[0142] Exemplary Example 4

[0143] This exemplary embodiment provides a computer-readable storage medium.

[0144] The computer-readable storage medium stores computer program instructions that, when executed by a processor, implement the method described in Example Embodiment 1 or 2.

[0145] The computer-readable storage medium can be any data storage device that stores data that can be read by a computer system. Examples of computer-readable storage media include: read-only memory, random access memory, read-only optical disc, magnetic tape, floppy disk, optical data storage device, and carrier waves (such as data transmission via the Internet through wired or wireless transmission paths).

[0146] Although the present invention has been described above in conjunction with exemplary embodiments and accompanying drawings, those skilled in the art should understand that various modifications can be made to the above embodiments without departing from the spirit and scope of the claims.

Claims

1. A method for generating a tension / compression member model of a perforated box girder, characterized in that, The method includes the following steps: (1) Determine the structural dimensions of the given perforated box girder and determine whether it is a two-dimensional or three-dimensional structure; (2) Perform structural modeling for the two-dimensional or three-dimensional structure; (3) Perform FEM analysis on the two-dimensional or three-dimensional structural model to obtain the structural topology; (4) Without changing the topological skeleton structure, delete the redundant mesh cells in the topological structure to obtain the optimization result; (5) Identify the nodes and members in the optimization results and combine them into a truss-like structure; (6) Reduce the number of tie rods to obtain an optimized truss-like structure; (7) Perform internal force calculations on the optimized truss-like structure to obtain the actual force on each member; (8) Calculate the deviation index of a single tie rod based on the actual force on each rod. S i and overall deviation index S And determine whether both are greater than the corresponding deviation index limit; (9) In S i and S If any one of the values ​​in the equation exceeds the corresponding tension / compression bar index limit, the truss-like structure is adjusted to meet the deviation index requirement and geometric constraint requirement, thus obtaining the model described above. The method further includes step (10): verifying the structural bearing capacity of the model obtained in step (9) and obtaining the reinforcement configuration; In step (5), the following node determination rules and member determination rules are followed, wherein, The node determination rules include: for two-dimensional nodes, a 3x3 grid centered on the node is detected, and if its average density is greater than or equal to 1 / 3, it is identified as a candidate node; load points and support points are also considered as candidate nodes; if the distance between two candidate nodes is less than 1.5 times the grid size, a single node is used to replace the node at the average position; for three-dimensional nodes, a 3x3x3 grid centered on the node is detected, and if its average density is greater than or equal to 1 / 9, it is considered a node. The rules for determining the members include: first, connecting each node directly through the members; then, deleting redundant members by comparing the number of grids traversed by the initial member connection path with the pixel repetition rate of the refined topology skeleton. In step (6), the number of members with lower tension is reduced by eliminating and merging short bars. This step includes: Set a minimum short bar size limit, iteratively check the length of all tie rods in the combined truss structure in step (5), and once the short bar size is less than the set limit, set the center position of the short bar as the new node position and eliminate the short bar; In step (8), S i and S The deviation index limits were 0.1 and 0.05, respectively; Calculate the following two formulas S i and S : ， ， in, N i and V i These are the axial force and shear force of the member corresponding to number i, respectively; The adjustment method in step (9) includes: adjusting the node position, setting the fluctuation range and the distance of each fluctuation.

2. The method for generating the tension / compression bar model of the perforated box girder according to claim 1, characterized in that, In step (2), a planar four-point unit is used to establish a structural model for a two-dimensional structure, and a three-dimensional solid eight-node unit is used to model a three-dimensional structure.

3. The method for generating the tension / compression bar model of the perforated box girder according to claim 1, characterized in that, In step (4), the topology is optimized by image conversion and removal of boundary pixels, wherein the image conversion includes converting the topology into binary data to obtain a binary image; The removal of boundary pixels includes iteratively removing boundary pixels from a binary image.

4. A computer device, characterized in that, include: At least one processor; A memory storing program instructions configured to be executed by the at least one processor, the program instructions including instructions for performing the method according to any one of claims 1-3.

5. A computer-readable storage medium having computer program instructions stored thereon, characterized in that, When the computer program instructions are executed by the processor, they implement the method of any one of claims 1-3.

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