A tensegrity ring structure

Abstract

The present invention provides a novel tensegrity ring structure, which includes 3n (n≥3) nodes, 2n diagonal compression bars, 2n stabilizing bars, 4n inclined cables and n vertical cables; n internal nodes are on a regular polygon plane with a radius of r, and each internal node is radially outward connected to 2 external nodes through 2 stabilizing bars with an included angle of α; 2n diagonal compression bars of equal length cross each other in pairs and are connected head to tail to the external nodes to form a regular polygon frustum as the outer ring of the ring tensegrity structure; each internal node is connected to the adjacent upper and lower external nodes of the regular polygon through 4 inclined cables, and 1 vertical cable is connected between the same group of upper and lower 2 external nodes. The present invention provides a novel ring tensegrity structure with good spatial symmetry and stability. This structure can effectively balance the circumferential pressure to bear the radial load, so it can be used as a self-balanced steel ring beam and has high application value in large-span space structure projects.

Description

Technical Field

[0001] The present invention relates to the design of tensegrity structures. Background Art

[0002] A tensegrity structure is a stable self - balancing structural system composed of a group of continuous tensile members and discrete compressive members. The stiffness of its structure consists of material stiffness and geometric stiffness. At the same time, the geometric shape and topological connection relationship of the structure must meet the condition of prestress self - balance. This kind of system has the advantages of light weight, high strength, controllable shape, reasonable force, novel shape, etc. It is the embodiment of new technology materials and structural forms in the field of structures, which has attracted the attention of many scholars and has been specifically applied in many practical projects.

[0003] Common tensegrity structure forms include geometric shapes such as spherical, flat - plate, multi - prism - shaped, etc., and there is relatively little research and exploration on new ring - shaped structures. As a completely self - balancing and rigid structure, the ring - shaped tensegrity structure can provide a tensile effect to the internal space, so it has important research significance. For the tensegrity ring, the form in which the compression bars are continuously crossed and distributed along the circumferential direction belongs to the Class - k ring - shaped tensegrity structure, which can transfer loads more evenly, is beneficial to balancing the circumferential pressure, and has better radial stiffness. However, so far, there are relatively few feasible ring - shaped tensegrity structure forms, and there is no ring - shaped tensegrity structure formed by continuously crossing compression bars. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a tensegrity ring structure, which is simple and efficient, can be applied to continuous cross - compression bars in practical projects, and is self - balancing.

[0005] The technical solution adopted by the present invention to solve the technical problem is as follows:

[0006] A tensegrity ring structure includes 3n (n≥3) nodes, 4n compression bar units, and 5n cable units. The compression bar units and the cable units are connected through the nodes.

[0007] The compression bar units include 2n diagonal compression bars and 2n stabilizing bars; the cable units include 4n diagonal cables and n vertical cables.

[0008] Further, the 3n nodes include n internal nodes and 2n external nodes. On a regular polygon plane with a radius of r, each internal node is connected to 2 external nodes along the radial direction outward through 2 stabilizing bars with an included angle of α.

[0009] Further, the 2n diagonal compression bars are of equal length. The 2n diagonal compression bars cross each other in pairs and are connected end - to - end to the external nodes, forming a regular polygon frustum as the outer ring of the ring - shaped tensegrity structure.

[0010] Furthermore, each internal node is connected to the upper and lower external nodes adjacent to the plane of the regular polygon with a radius of r by 4 inclined cables. In the same group, the upper and lower 2 external nodes are connected to each other by 1 vertical cable.

[0011] Furthermore, the plane where the stabilizing rod is located on each internal node is the normal plane of the circumscribed circle of the regular polygon passing through this node.

[0012] Furthermore, the planes of the regular polygons where all the internal nodes in the tensegrity ring structure are located are rotationally symmetric, and the rotation angle is 2π / n.

[0013] Furthermore, all the nodes are hinged nodes, and the strut elements and cable elements are only subjected to axial forces at the nodes; there is a pre-pressure in all the struts and a pre-tension in all the cables in the structure, and the overall structure satisfies prestress self-balancing.

[0014] Furthermore, the upper and lower stabilizing rods connected to the internal node have different lengths (h_1, h_2) and angles with the horizontal plane (α_1, α_2, and α = α_1 + α_2).

[0015] Furthermore, the annular tensegrity structure has 6 independent self-stress modes. The components in the structure are divided into six groups. The 2n inclined struts are the first group of components, the n upper stabilizing rods are the second group of components, the n lower stabilizing rods are the third group of components, the 2n upper inclined cables are the fourth group of components, the 2n lower inclined cables are the fifth group of components, and the n vertical cables are the sixth group of components; the lengths and prestress distributions of the components in the same group are the same.

[0016] The beneficial effects of the present invention are as follows:

[0017] (1) The present invention proposes a novel self-balancing tensegrity ring structure, which has the characteristics of simplicity, high efficiency, light weight, good symmetry, and large overall stiffness, enriching the design forms of the annular tensegrity structure.

[0018] (2) In the tensegrity ring structure of the present invention, there are continuous and intersecting struts distributed circumferentially, which can better balance the circumferential pressure and provide greater radial stiffness. The internal nodes can be conveniently used as tension connection points. At the same time, different from the requirement of complete symmetry of the existing annular tensegrity, the upper and lower surfaces of the outer ring can have different torus radii, which can enrich the geometric shape of the tensegrity ring structure.

[0019] (3) The tensegrity ring structure proposed by the present invention, as a completely self-balancing and rigid structure, can effectively provide radial tensile force, can be used to replace the fixed boundaries of traditional flexible structures such as cable domes and cable net structures to form a completely self-balancing system. At the same time, it can also be used as the tension boundary of temporary components such as tents and movable membrane surfaces, so it has important engineering practical significance. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is a top view of a tensegrity ring structure of the present invention.

[0021] Figure 2 is a side view of a tensegrity ring structure of the present invention.

[0022] Figure 3 is a perspective view of a tensegrity ring structure of the present invention.

[0023] Figure 4 is a schematic diagram of the design of the stabilizing bar of a tensegrity ring structure of the present invention.

[0024] Figure 5 is a schematic diagram of the node numbering of a tensegrity ring structure of the present invention.

[0025] Figure 6 is a schematic diagram of the numbering of the diagonal compression bar units of a tensegrity ring structure of the present invention.

[0026] Figure 7 is a schematic diagram of the numbering of the stabilizing bar units of a tensegrity ring structure of the present invention.

[0027] Figure 8 is a schematic diagram of the numbering of the inclined cable units of a tensegrity ring structure of the present invention.

[0028] Figure 9 is a schematic diagram of the numbering of the vertical cable units of a tensegrity ring structure of the present invention.

[0029] Figure 10 is in Example 1 of a tensegrity ring structure of the present invention, where n = 8, r = 4, , , , when it is a plan view.

[0030] Figure 11 is in Example 1 of a tensegrity ring structure of the present invention, where n = 8, r = 4, , , , when it is a perspective view.

[0031] Figure 12 is in Example 2 of a tensegrity ring structure of the present invention, where n = 10, r = 4, , , , when it is a plan view.

[0032] Figure 13In the second embodiment of the tensegrity ring structure of the present invention, n = 10, r = 4, , , , when it is a three-dimensional schematic diagram. Detailed implementation manners

[0033] In order to make the purpose, structural form and advantages of the present application clearer and more understandable, the following describes and explains the present application in combination with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application. Based on the embodiments provided by the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present application.

[0034] As shown in Figure 1 , 2 , 3, the present invention provides a tensegrity ring structure, including 3n (n≥3) nodes, 4n strut units, and 5n cable units. The struts and cables are connected through nodes, and all nodes are hinge nodes. The strut units and cable units can rotate at the nodes. The strut unit includes 2n diagonal struts and 2n stabilizing struts. The cable unit includes 4n diagonal cables and n vertical cables; n internal nodes are on a regular polygon plane with a radius of r. Each internal node is connected to 2 external nodes through 2 stabilizing struts with an included angle of α radially outward. The upper and lower external nodes at the same internal node are a group; 2n diagonal struts of equal length cross each other in pairs and connect the external nodes end to end to form a regular polygon frustum as the outer ring of the ring-shaped tensegrity structure; each internal node is connected to the adjacent upper and lower external nodes of the regular polygon through 4 diagonal cables, and 1 vertical cable is connected between the upper and lower 2 external nodes in the same group; the plane where the stabilizing struts are located on each internal node is the normal plane of the circumscribed circle of the regular polygon passing through this node; the tensegrity ring structure is rotationally symmetric about the regular polygon plane where the internal nodes are located, and the rotation angle is 2π / n.

[0035] The tensegrity ring structure of the present invention is uniquely determined by the following independent design parameters: the number of nodes n of the regular polygon of the internal nodes, the radius r of the circumscribed circle of the regular polygon of the internal nodes, the lengths of the upper and lower stabilizing struts , the included angles between the upper and lower stabilizing struts and the horizontal plane . The remaining structural parameters can be calculated from the above design parameters.

[0036] As shown in Figure 4 , all the external nodes fall on the upper and lower polygon planes. The radius of the upper polygon is , the radius of the lower polygon is . By taking different values for the parameter , tensegrity rings with different geometric shapes can be obtained.

[0037] The described annular tensegrity structure has 6 independent self-stress modes. There are pre-pressures in all compression bars and pre-tensions in all cables, and the overall structure satisfies prestress self-balancing. Considering symmetry, the components in the structure are divided into six groups. The 2n inclined compression bars are the first group of components, the n upper stabilizing bars are the second group of components, the n lower stabilizing bars are the third group of components, the 2n upper inclined cables are the fourth group of components, the 2n lower inclined cables are the fifth group of components, and the n vertical cables are the sixth group of components; the lengths and prestress distributions of the components in the same group are the same.

[0038] All the inclined compression bars have equal lengths, cross each other pairwise and are connected end to end to form a regular polygonal frustum as the outer ring of the annular tensegrity structure, whose function is to bear the circumferential pressure and provide the structural framework of the tensegrity ring; all the upper and lower inclined cables have corresponding equal lengths respectively, and all the vertical cables have equal lengths, whose function is to balance the bar forces and satisfy self-stress balance; the lengths of the above-mentioned bars are all determined by the number of nodes n of the regular polygon of the internal nodes, the radius r of the circumscribed circle of the regular polygon of the internal nodes, and the lengths of the upper and lower stabilizing bars , and the angles between the upper and lower stabilizing bars and the horizontal plane jointly determine...

[0039] As Figure 5 , 6 , 7, 8, 9 show, the nodes of the structure described in the present invention can be divided into n groups, each group contains 3 nodes, and the nodes of each group are rotationally symmetric about the normal line of the regular polygon of the internal nodes, and the rotation angle is 2π / n. The i-th group of nodes contains the nodes numbered 3i - 2, 3i - 1, 3i. The internal node 3i is on the regular polygon, and the external nodes 3i - 2, 3i - 1 are connected to the node 3i through stabilizing bars.

[0040] The coordinates involved in the present invention are:

[0041] i = 1, 2,... n

[0042] i = 1, 2,... n

[0043] i = 1, 2,... n

[0044] The topological connection form of the present invention is as follows:

[0045] 1) Inclined compression bar

[0046] An inclined compression bar 1 is connected between node 2 and node 3n - 2;

[0047] An inclined compression bar 2 is connected between node 1 and node 3n - 1;

[0048] A diagonal compression bar 2i - 1 is connected between node 3i - 5 and node 3i - 1, where i = 2, 3, …, n;

[0049] A diagonal compression bar 2i is connected between node 3i - 4 and node 3i - 2, where i = 2, 3, …, n.

[0050] 2) Stabilizing bar

[0051] An upper stabilizing bar 2i - 1 is connected between node 3i - 2 and node 3i, where i = 1, 2, 3, …, n;

[0052] A lower stabilizing bar 2i is connected between node 3i - 1 and node 3i, where i = 1, 2, 3, …, n.

[0053] 3) Diagonal cable

[0054] An upper diagonal cable 1 is connected between node 3 and node 3n - 2;

[0055] A lower diagonal cable 2 is connected between node 3 and node 3n - 1;

[0056] An upper diagonal cable 3 is connected between node 3n and node 1;

[0057] A lower diagonal cable 4 is connected between node 3n and node 2;

[0058] An upper diagonal cable 4i - 3 is connected between node 3i and node 3i - 5, where i = 2, 3, …, n;

[0059] A lower diagonal cable 4i - 2 is connected between node 3i and node 3i - 4, where i = 2, 3, …, n;

[0060] An upper diagonal cable 4i - 1 is connected between node 3(i - 1) and node 3i - 2, where i = 2, 3, …, n;

[0061] A lower diagonal cable 4i is connected between node 3(i - 1) and node 3i - 1, where i = 2, 3, …, n.

[0062] 4) Vertical cable

[0063] A vertical cable i is connected between node 3i - 2 and node 3i - 1, where i = 1, 2, 3, …, n.

[0064] The lengths of the components of the present invention are:

[0065] 1) Stabilizing bar: , ;

[0066] 2) Vertical cable: ;

[0067] 3) Diagonal compression bar: ;

[0068] 4) Oblique cables: , . Embodiment

[0069] As Figure 10 , 11 shown, the following parameters are selected: n = 8, r = 4, , , , As a specific embodiment of the tensegrity ring structure, the upper and lower toroidal surfaces of this structure have the same radius and are completely symmetric about the plane of the regular polygon where the internal nodes are located. Embodiment

[0070] As Figure 12 , 13 shown, the following parameters are selected: n = 10, r = 4, , , , As a specific embodiment of the tensegrity ring structure, the upper and lower toroidal surfaces of this structure have different radii and are asymmetric about the plane of the regular polygon where the internal nodes are located.

[0071] The above embodiments only represent several implementation manners of the present application. The description is relatively specific and detailed, but it should not be construed as a limitation on the scope of the invention patent. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of one or more embodiments of this specification shall be included within the protection scope of the present application.

Claims

1. A tensegrity ring structure, characterized in that, It includes 3n nodes, 4n strut elements, and 5n cable elements, where n≥3, and the strut elements and cable elements are connected by the nodes; The strut elements include 2n diagonal struts and 2n stabilizing struts; the cable elements include 4n diagonal cables and n vertical cables; The 3n nodes include n internal nodes and 2n external nodes. The n internal nodes are on the plane of a regular polygon with a radius of r. Each internal node is connected to 2 external nodes along the radial direction outward through 2 stabilizing struts with an included angle of α; The 2n diagonal struts are of equal length. The 2n diagonal struts cross each other in pairs and are connected end to end to the external nodes, forming a regular polygonal frustum as the outer ring of the annular tensegrity structure; Each internal node is connected to the upper and lower two external nodes adjacent to the plane of the regular polygon with a radius of r through 4 diagonal cables. In the same group, the upper and lower 2 external nodes are connected to each other through 1 vertical cable; The tensegrity ring structure has 6 independent self-stress modes. The members in the structure are divided into six groups. The 2n diagonal struts are the first group of members, the n upper stabilizing struts are the second group of members, the n lower stabilizing struts are the third group of members, the 2n upper diagonal cables are the fourth group of members, the 2n lower diagonal cables are the fifth group of members, and the n vertical cables are the sixth group of members; the lengths and prestress distributions of the members in the same group are the same.

2. The tensegrity ring structure according to claim 1, characterized in that, The plane where the stabilizing struts are located on each internal node is the normal plane of the circumscribed circle of the regular polygon passing through this node.

3. A tensegrity ring structure according to claim 1, characterized in that, The planes of the regular polygons where all the internal nodes are located in the tensegrity ring structure are rotationally symmetric, and the rotation angle is 2π / n.

4. The tensegrity ring structure according to claim 1, characterized in that: All the nodes are hinge joints. The strut elements and cable elements are only subjected to the axial forces of the nodes; there are pre-pressures in all the struts and pre-tensions in all the cables in the structure, and the overall structure satisfies prestress self-balancing.

5. A tensegrity ring structure according to claim 1, characterized in that: The upper and lower stabilizing struts connected to the internal node have different lengths h_1, h_2, and included angles α_1, α_2 with the horizontal plane, and α = α_1 + α_2.

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