A node positioning design method for spatial single-layer lattice shells

Abstract

The present invention relates to a spatial single-layer lattice shell node positioning design method, comprising: obtaining the number of rods; determining a vector along the direction of the rods; determining the normal vector of the plane between each adjacent rod; determining the positioning normal vector of the node; and completing the positioning and setting out of the node based on the positioning normal vector of the node. Compared with the prior art, the present invention determines the orientation vector of the rod connected to the node, finds the normal vectors of each plane surrounded by adjacent rods, and then obtains the normal vector of the node positioning by calculating the sum of the vectors. This solves the problem of the layout and positioning of the spatial lattice shell nodes in actual production. The bending and torsion of the steel plate generated by the connection between the designed and positioned node and each surrounding rod is the most uniform, and the total bending and torsion generated is the smallest, thereby ensuring the node effect and the feasibility of production. It can provide a mathematical basis for the positioning of nodes in spatial lattice shell structures or similar situations, and thereby achieve mass production and automation.

Description

Technical Field

[0001] The present invention relates to the technical field of building structure design, in particular to a spatial single-layer lattice shell node positioning design method. Background Art

[0002] As a building structure that combines both functionality and effectiveness, spatial gridshells are now widely used in various projects. Unlike traditional building structures, spatial gridshells offer a flexible and adaptable design. They are primarily composed of rods and intersections. The rods are interconnected to form a single triangular component, which in turn is formed into a curved surface. Therefore, spatial gridshells can achieve a near-curved form while minimizing the required structural volume and providing sufficient rigidity.

[0003] Currently, computer software is available in the field of spatial structures that can simulate and calculate the internal forces at the nodes and members of lattice shells. Most of these software utilize the finite element method, modeling steel components as bars converging at a single point to simulate the force relationships between the steel components and the intersection. While these software can calculate internal forces, they cannot provide a reference for detailed layout of the nodes.

[0004] The node production of the space grid shell is the most difficult part of the grid shell structure construction and processing, mainly in the following aspects: (1) the layout of the node itself: depending on the effect, the node itself will have different shapes, and its own tolerance and volume are not the same. If the node shape requires, the tolerance range between steel components will be very small, and it involves the bending and torsion layout of the steel plate, which is difficult to manufacture and requires high precision; (2) a large number of nodes and no repeated nodes: the number of nodes in the space grid shell structure is usually huge according to the scale. According to the design of the grid shell itself, although the nodes are similar, they are often different. The angle of the node itself and the bending and torsion between the node and the components determine the final layout shape. This difference can only be adjusted manually, which is time-consuming and labor-intensive, and the accuracy cannot meet the requirements. Summary of the Invention

[0005] The purpose of the present invention is to overcome the defects of the above-mentioned prior art and provide a spatial single-layer lattice shell node positioning design method, which can efficiently and accurately perform node layout design.

[0006] The object of the present invention can be achieved by the following technical solution: A spatial single-layer lattice shell node positioning design method comprises the following steps:

[0007] S1. Obtain the number of rods;

[0008] S2. Determine the vector along the direction of the rod;

[0009] S3. Determine the normal vector of the surface between each two adjacent rods based on the data obtained in step S2;

[0010] S4. Determine the positioning normal vector of the node based on the data result obtained in step S3;

[0011] S5. Based on the positioning normal vector of the node, complete the positioning and layout of the node.

[0012] Furthermore, the step S1 specifically obtains the number of rods connected to the node.

[0013] Furthermore, the step S2 specifically determines the unit vector along the direction of each rod.

[0014] Furthermore, the unit vectors along the direction of each rod in step S2 are specifically: in, n is the number of members connected to the node.

[0015] Furthermore, the step S3 specifically involves cross-producting the unit vectors of the two adjacent rods along the rod direction, that is, obtaining the normal vector of the surface between the two adjacent rods.

[0016] Furthermore, in step S3, the normal vector of the surface between each two adjacent rods is specifically: in,

[0017] Furthermore, the step S4 specifically includes the following steps:

[0018] S41, converting the data result obtained in step S3 into a unit vector;

[0019] S42. Calculate the node's positioning normal vector based on the data result obtained in step S41.

[0020] Furthermore, the unit vector obtained by the conversion in step S41 is specifically: in,

[0021]

[0022] Furthermore, the positioning normal vector of the node in step S42 is specifically the sum of the normal vectors of the surfaces between two adjacent rods:

[0023]

[0024] in, is the normal vector of the node.

[0025] Furthermore, the step S5 specifically uses the normal vector of the node as the direction of the node and the angle bisector of the angle between two adjacent rods as the orientation of the rod, thereby completing the positioning and setting out of the node.

[0026] Compared with the prior art, the present invention determines the orientation vector of the rod connected to the node, and determines the normal vector of each plane surrounded by adjacent rods, and then obtains the normal vector of the node positioning by calculating the vector sum. The node positioning and layout are completed according to the node positioning normal vector, which can ensure that the bending and torsion of the steel plate generated by the connection between the positioned node and each surrounding rod is the most uniform, and the total bending and torsion generated is the smallest, so as to minimize the node error, effectively improve the accuracy of node positioning, ensure the node effect and the feasibility of actual production. The method of the present invention can provide a mathematical basis for the positioning of nodes in spatial lattice shell structures or similar situations, and thereby realize mass production and automation. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 Schematic diagram of the method flow of the present invention;

[0028] Figure 2 Schematic diagram of the spatial single-layer lattice shell node positioning design method of the present invention;

[0029] Figure 3 Schematic diagram of the node positioning design method in the embodiment;

[0030] Figure 4 Schematic diagram of the rod direction positioning in the embodiment. DETAILED DESCRIPTION

[0031] The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0032] Example

[0033] like Figure 1 and Figure 2 As shown, a spatial single-layer lattice shell node positioning design method includes the following steps:

[0034] S1. Obtain the number of rods, specifically the number of rods connected to the node, denoted as n;

[0035] S2. Determine the vector along the direction of the rod, specifically the unit vector along the direction of each rod, denoted as in,

[0036] S3. According to the data obtained in step S2, the normal vector of the sandwich surface between each two adjacent rods is determined. Specifically, the normal vector of the sandwich surface between the two adjacent rods is obtained by cross-multiplying the unit vectors of the two adjacent rods along the rod direction, which is recorded as in,

[0037] S4. Determine the node's positioning normal vector based on the data obtained in step S3. Specifically:

[0038] First, the data result obtained in step S3 is converted into a unit vector, which is recorded as in,

[0039]

[0040] S42. Calculate the node's positioning normal vector based on the data obtained in step S41. The node's positioning normal vector is specifically the sum of the unit vectors of the normal vectors of the surfaces between two adjacent rods:

[0041]

[0042] in, is the normal vector of the node;

[0043] S5. Based on the positioning normal vector of the node, the positioning and setting out of the node is completed. Specifically, the normal vector of the node is used as the direction of the node, and the angle bisector of the angle between two adjacent rods is used as the orientation of the rod, thereby completing the positioning and setting out of the node.

[0044] This embodiment applies the above technical solution to design a space lattice shell. A node in the calculation model is as follows: Figure 3 As shown in the figure, this node is the intersection of 6 surrounding rods, all of which are box-section. During the detailed production of the node, it is required that the bending and torsion of the steel plate at the connection is as small as possible, and the bending and torsion amplitude of each node is as even as possible. The main process includes:

[0045] The first step is to determine the number of rods connected to the node. In this embodiment, the number of rods is 6, that is, n = 6;

[0046] The second step is to determine the unit vectors along the direction of each member, which are Figure 3 in and

[0047] The third step is to determine the normal vectors of the plane formed by every two adjacent rods, which are Figure 3 in The calculation method is ...and so on;

[0048] The fourth step is to convert each normal vector into a unit vector, recorded as The calculation method is ...and so on, eventually

[0049] The fifth step is to determine the normal vector of the node, that is Figure 3 The node normal vector in The calculation method is

[0050] The node normal vector calculated by the above process is the direction of the node. Usually the orientation of the member is the angle bisector of the angle between two adjacent faces (such as Figure 4 As shown), the torsion difference between the node deepened in this way and each member is the smallest, and the node normal vector calculated is The nodes positioned and staked out experience relatively even bending and torsion with the surrounding members, minimizing the total amount of bending and torsion. This ensures the quality and effectiveness of each node, even when the number of nodes is large. In actual fabrication, the required torsion of each member is evenly distributed, eliminating extreme individual cases. This ensures a uniform overall processing standard and better guarantees the design effect.

Claims

1. A spatial single-layer lattice shell node positioning design method, characterized in that: The following steps are involved: S1. Obtain the number of rods, specifically the number of rods connected to the node; S2. Determine the vector along the direction of the rod, specifically determine the unit vector along the direction of each rod. The unit vector along the direction of each rod is specifically: 、 … ,in, ; n is the number of members connected to the node; S3. Determine the normal vector of the surface between each two adjacent rods based on the data obtained in step S2. Specifically, the normal vector of the surface between each two adjacent rods is obtained by cross-multiplying the unit vectors of the two adjacent rods along the rod direction. The normal vector of the surface between each two adjacent rods is specifically: 、 … ,in, , … ; S4. Determine the positioning normal vector of the node based on the data result obtained in step S3; S5. Based on the positioning normal vector of the node, complete the positioning and setting out of the node; Step S4 specifically includes the following steps: S41, converting the data result obtained in step S3 into a unit vector, wherein the unit vector obtained by the conversion is specifically: 、 … ,in, , … ; ； S42. Calculate the node's positioning normal vector based on the data obtained in step S41. The node's positioning normal vector is specifically the sum of the unit vectors of the normal vectors of the surfaces between two adjacent rods: ， in, is the normal vector of the node; Step S5 specifically uses the normal vector of the node as the direction of the node and the angle bisector of the angle between two adjacent rods as the orientation of the rod, thereby completing the positioning and setting out of the node.

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