Parametric modeling method for steel truss dome structure based on grasshopper

Abstract

The application relates to a steel truss dome structure parameterization modeling method based on grasshopper, which comprises the following steps: 1) simplifying the modeling process into the form of a cluster group in grasshopper, so as to be directly called; 2) on a Rhino platform, specifying a reference point at an architectural curved surface modeling position, rotating and translating the architectural curved surface modeling to a coordinate origin, and taking the modeling surface at the origin as an input end architectural control surface; and 3) according to structure design requirements, customizing input end parameters, wherein the input end parameters comprise a ring segment number, a radial segment number, an inner offset distance of a structure control surface, a truss height and a ring truss node segment number between adjacent trusses, and are used for parameterization generation of a steel truss dome structure model. The application can directly capture the modeling curved surface of a building, utilize pre-set modular programming, and quickly generate a three-dimensional model for subsequent deepening structure design.

Description

Technical Field

[0001] This invention relates to the field of computer-aided structural design, specifically to the parametric-driven generation of dome structures. It is a rapid modeling method for steel truss dome structures based on the Rhino platform and using Grasshopper visual programming technology. Background Technology

[0002] Common dome structure designs include single-layer grid shells and cable-stayed domes. However, for buildings that require overall structural rigidity or have random heavy loads on their surfaces, truss structures are necessary.

[0003] This invention applies parametric design as the primary method to the modeling workflow of steel truss dome structures. It allows for the customization of input parameters based on the actual project conditions. These input parameters include the number of circumferential segments, the number of radial segments, the inner offset distance of the structural control surface, the truss height loss, and the number of circumferential truss node segments between adjacent trusses. These parameters are used to parametrically generate steel truss dome structure models, which helps improve the work efficiency of designers, optimize the design quality of projects, enhance the team's industry competitiveness, and reduce the manpower and time costs of design units. Summary of the Invention

[0004] The problem this invention aims to solve is to provide a parametric modeling method for steel truss dome structures. This method is beneficial for improving designers' work efficiency, optimizing project design quality, enhancing the team's industry competitiveness, and reducing the manpower and time costs for design units.

[0005] The technical solution provided by this invention is:

[0006] A parametric modeling method for steel truss dome structures based on Grasshopper includes the following steps:

[0007] 1) The modeling process is simplified to the form of clusters in Grasshopper for easy direct use;

[0008] 2) On the Rhino platform, specify the reference point for the architectural surface shape, rotate and translate the architectural surface shape to the origin, and use the shape surface at the origin as the input architectural control surface;

[0009] 3) Based on the structural design requirements, define the input parameters, including the number of circumferential segments, the number of radial segments, the inner offset distance of the structural control surface, the truss height loss, and the number of circumferential truss node segments between adjacent trusses, which are used to parametrically generate the steel truss dome structure model.

[0010] This invention can generate trusses that fit the building's shape surface with a custom setback distance by using variable design parameters and based on the characteristics of the building's shape; customize the number of continuous trusses, with non-continuous trusses converging at the top inner ring truss; and customize the number of middle ring trusses.

[0011] This invention allows users to directly input the bottom and top circle radii, surface height, and the location of the third point on the sweep line according to the architectural curved surface shape, and customize the output model dome surface as the input.

[0012] Step 3) of the present invention, after defining the input parameters, involves the following steps to parametrically generate the steel truss dome structure model:

[0013] (1) After customizing the input parameters, offset the building surface by the inner offset distance, filter out the bottom and top circles according to the building surface, draw the polygons according to the number of circumferential segments, and calculate the centroid position respectively.

[0014] (2) Draw the main truss: take the points at the same angle of the polygon and connect them with diagonal lines, project them onto the structural control surface, and divide them into segments according to the radial segment number to draw the upper chord of the structural truss; take out the surface normal vector of each point, select the middle point, draw the lower chord point according to the truss height, and connect the corresponding points to form vertical struts and diagonal web members.

[0015] (3) Draw the top inner ring truss: Determine the radius of the inner ring truss and select the radius of the inner ring truss; draw the planar polygon of the inner ring truss with the center point of the top circle, move it according to the normal vector direction and draw the lower chord point of the truss; take 1 / 3 point as the through truss, and the rest intersect in the inner ring truss;

[0016] (4) Draw the central ring truss: According to the design requirements, select the nodes at the same elevation where the central ring truss needs to be set, connect them with polyline and divide them into equal segments according to the number of controllable nodes; filter out the other central nodes except for the upper chord nodes of the truss, and find the lower chord nodes of the central truss by offsetting the surface normal vector; after sorting, connect them to form the vertical and diagonal web members of the central ring truss;

[0017] (5) Draw the top ring truss: According to the design requirements, select the nodes at the same elevation where the top ring truss needs to be set, connect them with polyline and divide them into equal segments according to the number of controllable nodes; filter the other middle nodes except the upper chord nodes of the truss, and find the lower chord nodes of the top ring truss by offsetting the surface normal vector; after sorting, connect them to form the vertical and diagonal web members of the top ring truss.

[0018] (6) Draw the radial secondary beam and the diagonal members at the bottom support: From the data of the upper chord of the middle ring truss, select the nodes of the radial secondary beam, the upper nodes of the diagonal members at the bottom support, and the corresponding supports, and draw the radial secondary beam and the diagonal members at the bottom support in sequence.

[0019] This invention is applied to the modeling workflow of steel truss dome structures. It allows for the customization of input control parameters such as the number of circumferential segments, the number of radial segments, the inner offset distance of the structural control surface, and the truss height loss, based on the actual project situation. These parameters are used to parametrically generate steel truss dome structure models, which helps improve the work efficiency of designers, optimize the design quality of projects, enhance the industry competitiveness of teams, and reduce the manpower and time costs of design units. Attached Figure Description

[0020] Figure 1 This invention provides a cluster program group for the parametric design of steel structure dome structures.

[0021] Figure 2 This is a schematic diagram of the generation of the steel dome structure of the present invention;

[0022] Figure 3 This is a schematic diagram of the generation of the steel dome structure of the present invention (II).

[0023] Figure 4 This is a workflow diagram for the parametric design of the steel dome structure modeling of the present invention. Detailed Implementation

[0024] The invention will now be further described with reference to the accompanying drawings.

[0025] This invention includes the following steps:

[0026] 1) The modeling process is simplified to the form of clusters in Grasshopper for easy direct use;

[0027] 2) On the Rhino platform, specify the reference point for the architectural surface shape, rotate and translate the architectural surface shape to the origin, and use the shape surface at the origin as the input architectural control surface;

[0028] 3) Based on the structural design requirements, define the input parameters, including the number of circumferential segments, the number of radial segments, the inner offset distance of the structural control surface, the truss height loss, and the number of circumferential truss node segments between adjacent trusses, which are used to parametrically generate the steel truss dome structure model.

[0029] This invention uses variable design parameters to generate trusses that fit the building's curved surface according to a custom setback distance, based on the characteristics of the building's curved shape; it also allows for a custom number of continuous trusses, with non-continuous trusses converging at the top inner ring truss; and a custom number of central ring trusses.

[0030] Input the bottom and top circle radii, surface height, and the location of the third point on the sweep line directly according to the architectural curved surface shape, and use the custom output modeled dome surface as the input.

[0031] Step 3) includes:

[0032] (1) After customizing the input parameters, offset the building surface by the inner offset distance, filter out the bottom and top circles according to the building surface, draw the polygons according to the number of circumferential segments, and calculate the centroid position respectively.

[0033] (2) Draw the main truss: take the points at the same angle of the polygon and connect them with diagonal lines, project them onto the structural control surface, and divide them into segments according to the radial segment number to draw the upper chord of the structural truss; take out the surface normal vector of each point, select the middle point, draw the lower chord point according to the truss height, and connect the corresponding points to form vertical struts and diagonal web members.

[0034] (3) Draw the top inner ring truss: Determine the radius of the inner ring truss and select the radius of the inner ring truss; draw the planar polygon of the inner ring truss with the center point of the top circle, move it according to the normal vector direction and draw the lower chord point of the truss; take 1 / 3 point as the through truss, and the rest intersect in the inner ring truss;

[0035] (4) Draw the central ring truss: According to the design requirements, select the nodes at the same elevation where the central ring truss needs to be set, connect them with polyline and divide them into equal segments according to the number of controllable nodes; filter out the other central nodes except for the upper chord nodes of the truss, and find the lower chord nodes of the central truss by offsetting the surface normal vector; after sorting, connect them to form the vertical and diagonal web members of the central ring truss;

[0036] (5) Draw the top ring truss: According to the design requirements, select the nodes at the same elevation where the top ring truss needs to be set, connect them with polyline and divide them into equal segments according to the number of controllable nodes; filter the other middle nodes except the upper chord nodes of the truss, and find the lower chord nodes of the top ring truss by offsetting the surface normal vector; after sorting, connect them to form the vertical and diagonal web members of the top ring truss.

[0037] (6) Draw the radial secondary beam and the diagonal members at the bottom support: From the data of the upper chord of the middle ring truss, select the nodes of the radial secondary beam, the upper nodes of the diagonal members at the bottom support, and the corresponding supports, and draw the radial secondary beam and the diagonal members at the bottom support in sequence.

[0038] See Figures 1-3 The specific steps of this invention are as follows:

[0039] The structural input parameters mainly include the following five parameters: the number of circumferential segments (m), the number of radial segments (n), the inner setback distance of the structural control surface, the truss height loss, and the number of circumferential truss node segments between adjacent trusses; cluster battery pack details Figure 1 ; Parameterized Workflow Details Figure 4 :

[0040] 1) Parametric design workflow for steel dome structure modeling;

[0041] 2) Pick the building's curved surface shape and calculate the vertical structural surface based on the setback distance;

[0042] 3) Divide the structure into equal segments along the circumference and draw the top and bottom polygons;

[0043] 4) Connect the points in order and project them onto the structural surface to draw the chord;

[0044] 5) Divide the upper chord into radial segments and move the normal vector according to the vector height to find the lower chord;

[0045] 6) Draw the vertical struts and diagonal web members of the main truss;

[0046] 7) Using the same principle, filter the points and draw the top inner ring truss and the middle ring truss;

[0047] 8) Sort and filter by points, and draw the diagonal bracing and radial secondary beams at the supports;

[0048] 9) Assigning cross-sections to form members. Wherein:

[0049] After offsetting the building surface by the inner offset distance, select the bottom and top circles based on the surface, draw polygons according to the number of circumferential segments, and calculate the centroid positions of each.

[0050] Main truss drawing: Connect points at the same angle on the polygon with diagonal lines, project them onto the structural control surface, and divide the structure into segments according to the radial segment number to draw the upper chord of the structural truss. Extract the surface normal vector of each point, select the middle points, draw the lower chord points according to the truss height, and connect the corresponding points to form the vertical struts and diagonal web members.

[0051] Drawing the inner ring truss at the top: Determine the radius of the inner ring truss. In this example, the smaller of 2 m and 0.5 times the radius of the top circle is selected as the radius of the inner ring truss. Using the center point of the top circle as the center point, construct the planar polygon of the inner ring truss. Similarly, move the polygon along the normal vector direction according to the height difference to draw the lower chord point of the truss. To avoid overly dense top members, only 1 / 3 of the points are taken as continuous trusses, with the rest converging within the inner ring truss.

[0052] Drawing the central ring truss: According to the design requirements, select the nodes at the same elevation where the central ring truss needs to be set, connect them with polylines, and divide the structure into equal segments according to the number of controllable nodes; filter the other central nodes except for the upper chord nodes, and calculate the lower chord nodes of the central truss by offsetting the surface normal vector; after sorting, connect them to form the vertical and diagonal web members of the central ring truss. The top ring truss is drawn according to the same principle.

[0053] Draw the radial secondary beams and the diagonal members at the bottom supports: From the data of the upper chord of the middle ring truss, select the nodes of the radial secondary beams, the upper nodes of the diagonal members at the bottom supports, and the corresponding supports, and connect them in sequence to draw the radial secondary beams and the diagonal members at the bottom supports.

Claims

1. A parametric modeling method for steel truss dome structures based on Grasshopper, comprising the following steps: 1) The modeling process is simplified to the form of clusters in Grasshopper for easy direct use; 2) On the Rhino platform, specify the reference point for the architectural surface shape, rotate and translate the architectural surface shape to the origin, and use the shape surface at the origin as the input architectural control surface; 3) Based on the structural design requirements, define the input parameters, including the number of circumferential segments, the number of radial segments, the inner setback distance of the structural control surface, the truss height, and the number of circumferential truss node segments between adjacent trusses. These parameters are used to parametrically generate the steel truss dome structure model, including: (1) After customizing the input parameters, offset the building surface by the inner offset distance, filter out the bottom and top circles according to the building surface, draw the polygons according to the number of circumferential segments, and calculate the centroid position respectively. (2) Draw the main truss: Take the points at the same angle of the polygon and connect them with oblique lines, project them onto the structural control surface, and divide them into segments according to the radial segment number to draw the upper chord of the structural truss; take out the surface normal vector of each point, select the middle point, draw the lower chord point according to the truss height, and connect the corresponding points to form vertical struts and diagonal web members. (3) Draw the top inner ring truss: Determine the radius of the inner ring truss and select the radius of the inner ring truss; draw the planar polygon of the inner ring truss with the center point of the top circle, move it according to the height in the direction of the normal vector, and draw the lower chord point of the truss; take 1 / 3 point as the through truss, and the rest intersect in the inner ring truss; (4) Draw the central ring truss: According to the design requirements, select the nodes at the same elevation where the central ring truss needs to be set, connect them with polyline and divide them into equal segments according to the number of controllable nodes; filter out the other central nodes except for the upper chord nodes of the truss, and find the lower chord nodes of the central truss by offsetting the surface normal vector; after sorting, connect them to form the vertical and diagonal web members of the central ring truss; (5) Draw the top ring truss: According to the design requirements, select the nodes at the same elevation where the top ring truss needs to be set, connect them with polyline and divide them into equal segments according to the number of controllable nodes; filter the other middle nodes except the upper chord nodes of the truss, and find the lower chord nodes of the top ring truss by offsetting the surface normal vector; after sorting, connect them to form the vertical and diagonal web members of the top ring truss. (6) Draw the radial secondary beam and the diagonal members at the bottom support: From the data of the upper chord of the middle ring truss, select the nodes of the radial secondary beam, the upper nodes of the diagonal members at the bottom support, and the corresponding supports, and draw the radial secondary beam and the diagonal members at the bottom support in sequence.

2. The parametric modeling method for steel truss dome structures based on Grasshopper according to claim 1, characterized in that, By using variable design parameters, based on the characteristics of the building's curved shape, the generated trusses are fitted to the building's shape surface with a custom setback distance; the number of continuous trusses is customized, and non-continuous trusses converge at the top inner ring truss; the number of middle ring trusses is customized.

3. The parametric modeling method for steel truss dome structures based on Grasshopper according to claim 1, characterized in that, Input the bottom and top circle radii, surface height, and the location of the third point on the sweep line directly according to the architectural curved surface shape, and use the custom output modeled dome surface as the input.

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