Implementation method for rapid construction of an edge-based complex spatial structure model

Abstract

A method for rapidly constructing a complex spatial structure model based on edges, which creates an optimized structural surface through a geometric algorithm and then meshes it to obtain a reasonably smooth mesh curve optimized structural surface, on which a lower chord optimized structure is created to generate a lower chord optimized structural model; finally, constraints and loads are applied to the generated lower chord optimized structural model, and overall structural models are generated in batches based on the optimized structural surface and the lower chord optimized structure. The present invention automatically generates optimized structural surfaces from architectural surfaces, boundaries, intersections, etc. using geometric algorithms, then meshes and generates lower chord structures, quickly creates large batches of structural models, supports multi-region linkage editing, and efficiently modifies complex structural models.

Description

Technical Field

[0001] The present invention relates to a technology in the field of architectural design, and specifically to a method for quickly constructing a complex space structure model based on edges. Background Art

[0002] Currently, the traditional modeling method for space structures is to build a model from points to lines and then to surfaces. Each modeling step takes a long time, and most of the work is repetitive. The accuracy is low and the modeling process is not intelligent and flexible enough. Modifying any geometric dimension is equivalent to rebuilding the model. With the increasingly widespread application of space structures, the forms of building structures are gradually becoming more complex, and the traditional modeling method can no longer meet the needs of designers. Summary of the Invention

[0003] Aiming at the prominent problems of the existing technology, such as the time-consuming, poor flexibility, and inability to efficiently compare models in the cumbersome modeling method from points to lines and then to surfaces for complex space structures, the present invention proposes a method for quickly constructing a complex space structure model based on edges. According to building surfaces, boundaries, intersection lines, etc., geometric algorithms are used to automatically generate optimized structural surfaces, and then mesh division and the generation of the lower chord structure are carried out to quickly create a large number of structural models. It supports multiple surface types, generates batch models, supports model linkage editing, automatically applies loads and boundaries, and has an automatic optimization function.

[0004] The present invention is realized through the following technical solutions:

[0005] The present invention relates to a method for quickly constructing a complex space structure model based on edges. After creating an optimized structural surface through geometric algorithms, mesh division is performed on it to obtain a reasonable and smooth mesh curve optimized structural surface. On this basis, the creation of the lower chord optimized structure is carried out to generate a lower chord optimized structure model; finally, constraints and loads are applied to the generated lower chord optimized structure model, and an overall structural model is batch-generated according to the optimized structural surface and the lower chord optimized structure.

[0006] The present invention relates to a system for implementing the above method, including: an optimized structural surface generation unit, a mesh optimization division unit, a lower chord optimized structure generation unit, and a batch overall optimization structure generation unit. Among them: the optimized structural surface generation unit automatically generates an optimized structural surface according to all geometric elements drawn and defined, using different geometric algorithms; the mesh optimization division unit optimizes the mesh division of all optimized structural surfaces according to the defined step length of the number of edge segments changed, the minimum number of segments, and the maximum number of segments; the lower chord optimized structure generation unit first obtains the minimum surface form of the optimized structural surface through form-finding analysis, then performs node projection to obtain the lower chord direction, and finally generates a lower chord optimized structure of a pyramid or a truss according to different thicknesses; the batch overall optimization structure generation unit creates an overall optimized structure model according to different optimized structural surfaces and lower chord optimized structures after applying constraints and loads.

[0007] The described optimized structure includes: an enclosing structure, a rotating structure, and a sweeping structure.

[0008] Technical effects

[0009] The present invention changes the traditional complex modeling method. Through the technology of constructing a basic framework composed of building surfaces, boundaries, and intersection lines and the mesh division optimization algorithm, the modeling time of complex space structures is shortened by more than 100%. Through multi-parameter mesh division optimization and variable thickness of the lower chord optimized structure, and multi-region linkage editing, the model modification efficiency is increased by more than 100%. By this method, a batch of models with different control parameters can be automatically established for comparison and optimization, so as to obtain the most reasonable structural model. Brief description of the drawings

[0010] Figure 1 It is a flow chart of the present invention;

[0011] Figure 2 It is a variable diagram of the force density form-finding method formula;

[0012] Figure 3 It is a schematic diagram of the structure of the embodiment;

[0013] Figure 4 It is a complete model diagram with a mesh division number of 12 and a lower chord thickness of 3 meters generated in the embodiment;

[0014] Figure 5 It is a comparison diagram of complete models with mesh division numbers of 12 and 15 in the embodiment;

[0015] Figure 6 It is a comparison diagram of complete models with lower chord thicknesses of 3 meters and 6 meters generated in the embodiment. Detailed implementation manners

[0016] As Figure 1 shown, this embodiment relates to a method for quickly constructing a complex space structure model based on edges, including:

[0017] Step 1: Create an optimized structure surface according to the enclosing structure geometric algorithm, the rotating structure geometric algorithm, and the sweeping structure geometric algorithm. Specifically: according to the geometric elements drawn and defined, an optimized structure surface is automatically generated.

[0018] The described geometric elements include but are not limited to: all surfaces, surface intersection lines, curves on the surface, edges, generatrices, axes, angles, and guide wires, etc.

[0019] The enclosing structure geometric algorithm refers to: generating a surface by connecting the head and tail of the characteristic points of the edge line in sequence to form a closed loop.

[0020] The described geometric algorithm for the rotation structure means that each bus feature point P after rotating by θ around the axis is P(θ) = P · MAT rot (θ), where: the rotation angle θ ∈ [θ b , θ e , and MAT rot is the rotation matrix.

[0021] The described geometric algorithm for the sweeping structure means that each bus feature point P after sweeping is P' = P · MAT transf · MAT rot · MAT scalr , where: MAT transf is the translation matrix, and MAT scale is the scaling matrix.

[0022] The described generation of the optimized structure surface means that according to the edge number variation step Ns, the minimum number Nmin, and the maximum number Nmax, the model edge number n = {Nmin, Nmin + Ns, Nmin + 2Ns,..., Nmax} is obtained, and then x kinds of optimized structure surfaces are generated, where x = (Nmax - Nmin) / Ns.

[0023] Step 2: Mesh the optimized structure surface, including:

[0024] Step 2.1) Obtain the optimal mesh division parameters according to the set Jacobian ratio, aspect ratio, and smoothness;

[0025] The described optimal mesh division parameters include: the shape of the internal grid lines, the number of grid line divisions, and the grid line division nodes.

[0026] Step 2.2) Mesh the x groups of models with different numbers according to the optimal mesh division parameters to generate a reasonably smooth grid curve structure surface;

[0027] The described mesh division algorithm means that all grids are formed by connecting adjacent division nodes of all internal grid lines.

[0028] Step 3: Generate the lower chord optimized structure model, including:

[0029] Step 3.1) Obtain the minimum surface form of the optimized structure surface through the force density form-finding method. Specifically: first set the basic parameters, then calculate the force density of the structure and the force density values of each rod, so as to determine the prestress in the structure configuration. As Figure 2 shown, the equilibrium equation at each node in the structure is represented by the force density and the ropes connected to the node. The coordinate difference between the node and the nodes connecting the node is related to the force density, and the force density is in equilibrium with the external load. Thus, the equilibrium equation Aq = p is established, where: q is the force density vector of the rod, p is the external load acting on the node, and the equilibrium matrix of the rods in the structure system The force density matrix D = C T diag(q)C, where C is the connectivity matrix, and the elements of the force density matrix are summed up.

[0030] The basic parameters described above include: the topological configuration of the structure, namely, finding the connectivity matrix, boundary constraint conditions, and internal forces in the equilibrium state.

[0031] Step 3.2) Project the nodes of the optimized structural surface onto a specified surface to achieve a specific shape of the structural surface, including:

[0032] 3.2.1) Select any projection surface, and project the upper chord nodes of the optimized structure obtained in all steps of Step 2 onto this surface;

[0033] 3.2.2) Calculate the projection vector through any one of the following methods:

[0034] a) Fix the projection vector, that is, the nodes are directly projected onto the specified surface through this projection vector;

[0035] b) Calculate the projection vector with reference to a point, that is, take the vector from the reference point to each node as the projection vector of this node and project it onto the specified surface;

[0036] c) Calculate the projection vector with reference to an axis, that is, draw a perpendicular line from each node to the reference axis to obtain the foot of the perpendicular, and take the vector from the foot of the perpendicular to this node as the projection vector and project it onto the specified surface.

[0037] Step 3.3) According to the thickness change step Ts of the optimized structural surface, the minimum thickness Tmin, and the maximum thickness Tmax, calculate the number of wire segments t = {Tmin, Tmin + Ts, Tmin + 2Ts,..., Tmax}, and then generate y different lower chord optimized structures, where y = (Tmax - Tmin) / Ts;

[0038] Step 3.4) Generate the lower chord optimized structures of different thickness pyramids or trusses according to the thickness coefficients of the defined corner points and centroid points or the thickness change law on the generatrix side.

[0039] The thickness change law described above refers to the linear interpolation law of thickness for the lines formed by corner points and corner points, the lines formed by corner points and centroid points, and the generatrix.

[0040] Step Four: Apply constraint and load information to the lower chord optimized structural model respectively, including:

[0041] Step 4.1) Apply translational constraints in the X, Y, and Z directions and rotational constraints about the X, Y, and Z axes to the lower chord optimized structural model according to the node constraint conditions and the number of node intervals on the side.

[0042] Step 4.2) Apply loads to the optimized structural surface of the optimized lower chord structural model according to the load cases and the load calculation methods for each case.

[0043] The load cases mentioned above include: self-weight, dead load, live load, wind load, temperature effect, horizontal seismic action, vertical seismic action, crane load, and support displacement.

[0044] Step Five: Create an overall optimized structural model and perform multi-region linkage editing, including:

[0045] Step 5.1) Create S overall optimized structural models based on x optimized structural surfaces and y optimized lower chord structures, where S = x * y.

[0046] Step 5.2) Modify the number of edge segments of the structural surface of the overall optimized structural model and the thickness of the optimized lower chord structure, and perform multi-region linkage editing on the model.

[0047] Through specific actual experiments, taking a double-sphere plus cylindrical reticulated shell structure with a length of about 125.5 meters as an example, the structure includes two spherical reticulated shells and a cylindrical reticulated shell, where: the two end spherical reticulated shells intersect with the middle cylindrical reticulated shell; the radius of spherical reticulated shell 1 is 20 meters, the radius of spherical reticulated shell 2 is 30 meters, the distance between the two sphere centers is 80 meters, the middle is the cylindrical reticulated shell, the centers of spherical reticulated shell 1 and the cylindrical reticulated shell are on the same horizontal line, and the center of spherical reticulated shell 2 sinks 5 meters.

[0048] After the above steps, 5 groups of enclosure structures and 2 groups of rotary structures as shown in Figure 3 are automatically established using the geometric algorithm, where the rotation angle of rotary structure 1 is (0°, 180°), and the rotation angle of rotary structure 2 is (0°, 200°). The optimized structural surface is meshed according to the number of segments 12, 13, 14, 15, 16, and the optimized lower chord structure generates a lower chord pyramid structure according to the thickness of 3m, 4m, 5m, 6m, and finally 20 groups of models with different optimized structural surfaces and lower chord structures are formed.

[0049] As shown in Figure 4 is the complete model diagram with the number of mesh segments 12 and the lower chord thickness of 3 meters generated.

[0050] As shown in Figure 5 is the comparison diagram of the complete models with the number of mesh segments 12 and 15.

[0051] As shown in Figure 6 is the comparison diagram of the complete models with the lower chord thickness of 3 meters and 6 meters generated.

[0052] The total modeling time for the above 20 groups of optimized structures is within 30 minutes, while it takes more than 3 days to complete the modeling of 1 group of models using the traditional point-to-line-to-surface modeling method.

[0053] As Figure 4 shown, taking the structure with the optimized structural surface grid number of 12 and the lower chord pyramid thickness of 3 m as an example, the total number of components is 4293. When the grid division number changes from 12 to 15 as Figure 5 shown, and the total number of components increases to 8699, by using the present method, only the side number needs to be changed, and the model with the optimized structural surface grid number of 15 can be completed within 1 min, and almost no time is required for re-modeling. While according to the traditional modeling method, the model needs to be re-established, that is, it takes more than 3 days to re-model. Similarly, as Figure 6 shown, when the lower chord optimized structure thickness is changed from 3 m to 6 m or other thicknesses, only the thickness parameter needs to be adjusted. By using the present method, the comparative optimization of the structural models with different optimized structural surface grid division numbers and lower chord thicknesses can be automatically completed to find the optimal structure.

[0054] Compared with the prior art, the present invention shortens the modeling time of complex space structures by more than 100% through the technology of the basic framework composed of building surfaces, boundaries and intersection lines and the grid division optimization algorithm. Through multi-parameter grid division optimization, variable thickness of the lower chord optimized structure and multi-region linkage editing, the model modification efficiency is increased by more than 100%. By using the present method, a large number of models with different control parameters can be automatically established for comparative optimization, so as to obtain the most reasonable structural model.

[0055] The above specific implementation can be locally adjusted in different ways by those skilled in the art without departing from the principles and purposes of the present invention. The protection scope of the present invention is subject to the claims and is not limited by the above specific implementation, and each implementation within its scope is subject to the present invention.

Claims

1. A method for quickly constructing and implementing an edge-based complex space structure model, characterized in that, Specifically include: Step 1: Create an optimized structural surface according to the enclosure structure geometric algorithm, the rotary structure geometric algorithm, and the sweeping structure geometric algorithm. Specifically: Automatically generate an optimized structural surface according to the drawn and defined geometric elements. Step 2: Perform mesh division on the optimized structural surface, including: Step 2.1: Obtain the optimal mesh division parameters according to the set Jacobian ratio, aspect ratio, and smoothness. Step 2.2: Perform mesh division on x groups of models with different numbers of copies according to the optimal mesh division parameters to generate a reasonable and smooth mesh curve structural surface. Step 3: Generate a lower chord optimized structural model, including: Step 3.1) Obtain the minimum surface form of the optimized structural surface through the form-finding method of force density. Specifically: First, set the basic parameters, then calculate the force density of the structure and the force density values of each rod, so as to determine the prestress in the structural configuration. The equilibrium equation at each node in the structure is represented by the force density and the cables connected to the node. The coordinate difference between the nodes and the nodes connecting the nodes is related to the force density, and the force density is in equilibrium with the external load. Thus, establish the equilibrium equation Aq = p, where: q is the force density vector of the rod, p is the external load acting on the node, and the equilibrium matrix of the rods in the structural system The force density matrix D = C T diag(q)C, where C is the connection matrix; Step 3.2: Project the nodes of the optimized structural surface to a specified surface to achieve a specific shape of the structural surface, including: 3.2.1: Select any projection surface, and project the upper chord nodes of the optimized structural surface obtained in all Step 2 to this surface. 3.2.2: Calculate the projection vector in any of the following ways: a) Fix the projection vector, that is, the nodes are directly projected to the specified surface through this projection vector. b) Calculate the projection vector by reference point, that is, take the vector from the reference point to each node as the projection vector of this node and project it to the specified surface. c) Calculate the projection vector by reference axis, that is, draw a perpendicular line from each node to the reference axis to obtain the foot of the perpendicular, and take the vector from the foot of the perpendicular to this node as the projection vector and project it to the specified surface. Step 3.3: According to the thickness change step Ts, the minimum thickness Tmin, and the maximum thickness Tmax of the optimized structural surface, calculate the number of wire copies t = {Tmin, Tmin + Ts, Tmin + 2Ts,..., Tmax}, and then generate y different lower chord optimized structures, y = (Tmax - Tmin) / Ts; Step 3.4: Generate a lower chord optimized structure of different thickness pyramids or trusses according to the thickness coefficients of the defined corner points and centroid points or the thickness change law on the generatrix side. Step 4: Apply constraint and load information to the lower chord optimized structural model respectively, including: Step 4.1: Apply translational constraints in the X, Y, and Z directions and rotational constraints about the X, Y, and Z axes to the lower chord optimized structural model according to the node constraint conditions and the number of intervals of the edge nodes. Step 4.2: Apply loads to the optimized structural surface of the lower chord optimized structural model according to the load conditions and the load calculation methods for each condition. Step 5: Create an overall optimized structural model and perform multi-region linkage editing, including: Step 5.1: Create S overall optimized structural models according to x kinds of optimized structural surfaces and y kinds of lower chord optimized structures, where S = x * y; Step 5.2: Modify the number of edge copies of the structural surface of the overall optimized structural model and the thickness of the lower chord optimized structure, and perform multi-region linkage editing on the model.

2. The method for quickly constructing and implementing an edge-based complex space structure model according to claim 1, characterized in that, The enclosure structure geometric algorithm mentioned refers to: Generating a surface by connecting the head and tail of the edge feature points in sequence for closing. The described geometric algorithm for the rotary structure means that each bus feature point P after rotating by θ around the axis is P(θ) = P · MAT rot (θ), where: the rotation angle θ ∈ [θ b , θ e , MAT rot is the rotation matrix; The described sweeping structure geometric algorithm means that each bus feature point P after sweeping is P' = P · MAT transf · MAT rot · MAT scale , where: MAT transf is the translation matrix, and MAT scale is the scaling matrix.

3. The method for quickly constructing and implementing an edge-based complex space structure model according to claim 1, characterized in that, The generation of the optimized structural surface refers to: According to the edge copy change step Ns, the minimum number of copies Nmin, and the maximum number of copies Nmax, calculate the number of model edge copies n = {Nmin, Nmin + Ns, Nmin + 2Ns,..., Nmax}, and then generate x kinds of optimized structural surfaces, x = (Nmax - Nmin) / Ns.

4. The method for quickly constructing and implementing an edge-based complex space structure model according to claim 1, characterized in that, The described thickness variation law refers to the linear interpolation law of thickness for the lines formed by corner points, the lines formed by corner points and the centroid, and the generatrix. The described optimal mesh division parameters include: the shape of the inner grid lines, the number of grid line divisions, and the grid line division nodes. The described basic parameters include: the topological configuration of the structure, that is, the connection matrix, boundary constraint conditions, and internal forces in the equilibrium state.

5. The method for quickly constructing and implementing an edge-based complex space structure model according to claim 1, characterized in that, The described loads include: dead loads and live loads.

6. A system for implementing the method for quickly constructing a complex spatial structure model based on edges according to any one of claims 1-5, characterized in that, Include: An optimized structural surface generation unit, a mesh optimization division unit, a lower chord optimized structure generation unit, and a batch overall optimized structure generation unit. Among them: The optimized structural surface generation unit automatically generates an optimized structural surface according to all the geometric elements drawn and defined, using different geometric algorithms; the mesh optimization division unit optimizes the mesh division of all optimized structural surfaces according to the defined step length of the number of edge divisions, the minimum number of divisions, and the maximum number of divisions; the lower chord optimized structure generation unit first obtains the minimum surface form of the optimized structural surface through form-finding analysis, then projects the nodes to obtain the lower chord direction, and finally generates the lower chord optimized structure of a pyramid or a truss according to different thicknesses; the batch overall optimized structure generation unit creates an overall optimized structure model according to different optimized structural surfaces and lower chord optimized structures after applying constraints and loads.

7. The system according to claim 6, characterized in that, The described optimized structures include: enclosing structures, rotating structures, and sweeping structures.

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