An assembled dome structure integrated by annular tensegrity modules

Abstract

The present invention provides an assembled dome structure composed of annular tensegrity modules. This system is constructed by assembling an N-sided annular tensegrity structure in a circle packing grid pattern similar to that of a sphere. The assembled dome structure is completely self-balancing. Compared to traditional cable domes, the self-balancing dome structure of the present invention does not require a rigid ring beam and can be constructed using an assembled construction method. This significantly speeds up construction and reduces costs, while also providing greater overall structural robustness. Therefore, this structural form has significant application prospects.

Description

Technical Field

[0001] The invention discloses an assembled integrated cable-rod structure system, relates to the technical field of space structures in civil engineering, and particularly relates to an assembled dome structure integrated with annular tensegrity modules. Background Art

[0002] With the development of modern economic and social activities, people have a greater demand for large-span roof structures and have also put forward higher requirements for construction and use. Cable-strut tension structure systems, especially cable dome structures, are widely used in the construction of various large-span building roofs because of their simple and efficient force transmission method, which can maximize the utilization of material and cross-sectional properties. They have the characteristics of light weight, large span, and reasonable force distribution. However, existing cable dome structures usually still have some inevitable shortcomings. For example, they require rigid ring beams or stable fixing points to provide sufficient tensioning force. The construction process requires the use of a large amount of auxiliary installation equipment such as scaffolding and tooling cables. The on-site construction workload is large and the construction is difficult, making it difficult to achieve prefabricated construction. In addition, damage to local rods can easily cause continuous collapse and damage of the structure. The above problems seriously restrict the further promotion and application of cable dome structures. Therefore, it is necessary to explore new cable-strut structures to meet the construction needs of roof structures.

[0003] The tensegrity structure is a special cable-strut tension system with self-balancing characteristics. However, there is currently a lack of relevant exploration of the construction of self-balancing roof structures based on the concept of tensegrity. At the same time, prefabricated construction technology is an important trend in the development of the construction industry, and the current development of prefabricated prestressed spatial structures in my country still needs to be vigorously promoted and has huge application prospects. Therefore, based on the existing annular tensegrity structure (CN201910021688.4), the present invention proposes to construct a completely self-balancing dome structure through modular integration in an assembled manner, which has important research significance. Summary of the Invention

[0004] The purpose of the present invention is to provide an assembled dome structure integrated by annular tensegrity modules, and to explore a new type of roof structure that can be assembled, fully self-balanced and has good structural robustness.

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

[0006] An assembled dome structure composed of annular tensegrity modules is obtained by assembling an N-gonal annular tensegrity structure according to a circle packing grid on the surface of a sphere. The assembled dome structure is a fully self-balancing dome structure.

[0007] The described circle packing grid is distributed within the area enclosed by the boundary curve on the design spherical surface with a radius of R. It is a set of tangent circle patterns corresponding to the triangulated grid. Based on the triangular grid, the centers of the individual packing circles within the circle packing grid are distributed at the vertices of the triangular grid and are tangent to adjacent packing circles on the grid edges connected to the vertices of the triangular grid they are located in. The three packing circles of any triangular grid are pairwise tangent; all the packing circles are restricted by the boundary curve and the design spherical surface and jointly form a dense packing grid within the spherical area enclosed by the boundary curve; since all the packing circles are located on the standard design spherical surface, the normal directions of the packing circle surfaces all point to the center of the sphere.

[0008] The described N-sided ring tensegrity structure as an assemblable basic module includes 3N nodes, N circumferential rods, 2N stabilizing rods, 4N diagonal cables, and N vertical cables; the N circumferential rods are joined end to end to form a polygonal inner ring with a radius of r, and all the circumferential rods are in the same plane; at each node of the inner ring polygon, 2 stabilizing rods are connected. The outer ends of the 2 stabilizing rods are each connected to adjacent nodes of the polygon through 2 diagonal cables, and the outer ends of the 2 stabilizing rods are connected to each other through 1 vertical cable; the plane where the stabilizing rods connected to each node of the inner ring polygon are located is the normal plane of the circumscribed circle of the polygon passing through this node.

[0009] Furthermore, the packing circles distributed on the spherical surface are extruded inward by a thickness of h along their circumferences in the normal direction of the design spherical surface to form a frustum of a cone with a generatrix of l. The frustum of the cone is the filling space of the tensegrity module; the generatrix of the frustum of the cone extends and intersects at the center of the design spherical surface, and the upper and lower bases of the frustum of the cone are respectively tangent.

[0010] Furthermore, the tangent points of the upper and lower bases of adjacent frustums of the cone are used as a pair of connection points between the frustums of the cone. The extension line of the connection line of this pair of connection points converges at the center of the design spherical surface; the three frustums of the cone on any triangular grid are pairwise connected through three pairs of connection points to form a stable triangulated assembly pattern, and all the modules are assembled to the overall structure in this pattern.

[0011] Furthermore, the ring tensegrity module is filled in the frustum of the cone space. The outer ends of the stabilizing rods of the ring tensegrity are placed at the connection points, and different modules are assembled by sharing the connection points; the tensegrity inner ring is on the plane intercepted by the median line of the frustum of the cone. The radius r of the circumscribed circle of the inner ring node is obtained by multiplying the radius r′ of the circle intercepted by the median line of the frustum of the cone by a reduction ratio k (0 < k < 1), that is, r = kr′.

[0012] Furthermore, the number of edges of the annular tensegrity that fills the internal cone of the design area is determined by the number of cones tangent to the cone, and the position of each node is determined by the position of the connection point; the number of edges and node positions of the tensegrity that fills the cone at the boundary curve, the part tangent to the internal cone is determined by the number and position of the connection points, and the part close to the boundary curve is artificially processed to increase the number of edges of the annular tensegrity structure and determine the position of the nodes, so that it forms a complete and stable module.

[0013] Furthermore, the nodes are all hinged nodes, and spherical joints are provided at all nodes, so that the rod units and cable units can rotate at the nodes.

[0014] Furthermore, the structural system can be constructed in an assembled manner: first, the cross-sectional dimensions and cutting lengths of each component under zero stress are determined based on the form-finding and force-finding results of each tensegrity module, cutting is performed in the factory, and each annular tensegrity module is assembled and formed; secondly, after each module is hoisted into place at the construction site, the vertical cables between the connection points of the tension modules are tightened to apply prestress to the overall structure; after all modules are installed, the construction auxiliary facilities and the repeated vertical cables in the connection parts of the modules are removed, and the overall dome structure is completed.

[0015] The beneficial effects of the present invention are:

[0016] 1. The present invention provides a completely self-balancing cable-strut system dome structure. Compared with the traditional cable dome structure, it does not require the construction of rigid ring beams or strong tensioning nodes, which can effectively save construction costs.

[0017] 2. The overall structure created by the present invention in a modular assembly manner can be completed through assembly construction. The cutting of components and assembly of modules are completed in the factory, and then the modules are assembled on site to realize the overall construction. This can greatly speed up the construction speed, reduce the construction difficulty, and reduce the construction cost, and meet the development requirements of industrialization, assembly, and greening of large-span spatial structures.

[0018] 3. Since the dome structure of the present invention is assembled from multiple self-balancing tensegrity modules, the assembly method is a stable triangulated assembly mode, in which damage to the components of a local module has little impact on the stability and bearing capacity of other modules, thus having strong structural robustness.

[0019] 4. The structural configuration proposed in this invention, due to its self-balancing, rapid construction, and overall mobility, is applicable in a wide range of scenarios. It can be used not only as a large-span roof structure, but also as a temporary canopy, a temporary post-disaster roof, and other architectural features. Therefore, this structural system further enriches the types of spatial structures and has significant research and practical value. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] FIG1( a ) is a design area on a spherical surface in the present invention.

[0021] FIG1( b ) is a schematic diagram of a circle-filled grid within a spherical design area in the present invention.

[0022] Figure 2 This is a schematic diagram of the tangency between a filling circle near a vertex of the triangular mesh and other filling circles in the present invention.

[0023] Figure 3 (a) is a schematic diagram of a single truncated cone extruded along the spherical surface normal direction by a circular filling grid within the design area in the present invention.

[0024] FIG3( b ) is a schematic diagram of multiple frustums extruded along the normal direction of the sphere from the circular filling grid in the design area in the present invention.

[0025] FIG. 4( a ) is a schematic diagram of three tangent circles on a triangular grid in the basic triangulated assembly mode of the annular tensegrity module of the present invention.

[0026] FIG4( b ) is a schematic diagram of the extrusion process along the normal line in the basic triangulated assembly mode of the annular tensegrity module of the present invention.

[0027] FIG4( c ) is a schematic diagram showing the generation of a triangulated assembly space in the basic triangulated assembly mode of the annular tensegrity module of the present invention.

[0028] Figure 5 This is a schematic diagram of an assemblable annular tensegrity module in the present invention.

[0029] FIG6( a ) is a three-dimensional view of a tensegrity module filled into a truncated cone according to the present invention.

[0030] FIG6( b ) is a side view of the tensegrity module filled into the truncated cone according to the present invention.

[0031] Figure 7 It is a schematic diagram of the modification of the tensegrity module at the boundary curve in the present invention.

[0032] Figure 8 Schematic diagram of a circle-filled grid in Example 1 of the present invention.

[0033] Figure 9 It is a top view of the structure of Example 1 of the present invention.

[0034] Figure 10 It is a structural stereogram of Example 1 of the present invention.

[0035] Figure 11 Schematic diagram of a circle-filled grid in Example 2 of the present invention.

[0036] Figure 12It is a top view of the structure of Example 2 of the present invention.

[0037] Figure 13 It is a structural stereogram of Example 2 of the present invention. DETAILED DESCRIPTION

[0038] In order to make the purpose, technical solutions and advantages of this application more clearly understood, the present application is described and illustrated below in conjunction with the accompanying drawings and examples. It should be understood that the specific embodiments described herein are merely used to explain this application and are not intended to limit this application. Based on the embodiments provided in this application, all other embodiments obtained by those of ordinary skill in the art without creative work are within the scope of protection of this application.

[0039] The present invention provides an assemblable dome structure integrated with annular tensegrity modules. The structural system is assembled by filling an annular tensegrity module into a truncated cone space transformed from a circular filling grid on the surface of a sphere. The specific design and construction process is as follows:

[0040] As shown in Figure 1-2, on the design sphere with a radius of R, a plane is used to cut the sphere to obtain a spherical segment with a height of H. The intersection line of the cross section is the boundary curve, and the surface of the spherical segment inside the boundary curve is the design area.

[0041] The circle-filled mesh generated within the design area is based on a triangular mesh and consists of a set of tangent circles corresponding to the triangulated mesh. Each circle a in the circle-filled mesh is located at the vertex b' of the triangular mesh b. Adjacent circles are tangent to the mesh edges (triangle sides) connecting the vertices of their respective triangular meshes. Any three circles in any triangular mesh are tangent to each other. All circles in the resulting mesh meet these tangent conditions.

[0042] In addition to the above-mentioned tangency conditions, all filling circles are also constrained by the boundary curve and the design sphere, forming a dense filling grid within the spherical area enclosed by the boundary curve. Since all filling circles are located on the standard design sphere, the normal directions of the filling circle surfaces all point to the center of the sphere.

[0043] As shown in Figure 3, to create a three-dimensional space filled with assembled modules, the filling circles distributed on the sphere's surface are extruded inward along their circumference, in the direction normal to the designed sphere, by a thickness of h. This forms a truncated cone with a generatrix l. This truncated cone serves as the filling space for the tensegrity module. Because all filling circles are extruded along the normal, the generatrixes of all the resulting truncated cones converge at the center of the designed sphere, and the upper and lower bases of the cones are tangent to each other.

[0044] As shown in Figure 4, the tangent points of the upper and lower bases of any two adjacent frustums of a cone are used as a pair of connection points between the two frustums of a cone, and the extension line of the connection line of this pair of connection points intersects at the center of the designed spherical surface; the three frustums of a cone on any triangular grid are connected pairwise through three pairs of connection points to form a stable triangulated assembly mode. Since the obtained circular filling grid is based on a triangulated grid and all modules are assembled onto the overall structure according to this mode, the overall assembled structure is stable and valid.

[0045] As Figure 5 shown, the present invention uses an existing annular tensegrity structure (CN201910021688.4) as a basic assemblable module. The N-sided annular tensegrity module includes 3N nodes, N circumferential rods, 2N stabilizing rods, 4N inclined cables, and N vertical cables; the N circumferential rods are connected end to end to form a polygonal inner ring with a radius of r, and all circumferential rods are in the same plane; at each node of the inner ring polygon, 2 stabilizing rods are connected, and the outer ends of the 2 stabilizing rods are each connected to adjacent nodes of the polygon through 2 inclined cables, and the outer ends of the 2 stabilizing rods are connected to each other through 1 vertical cable; the plane where the stabilizing rods connected to each node of the inner ring polygon are located is the normal plane of the circumscribed circle of the polygon passing through this node.

[0046] As Figure 6(a)-Figure 6(b) shown, the annular tensegrity module is filled in the frustum space. The outer ends of the stabilizing rods of the annular tensegrity are placed at the connection points, and the modules in adjacent frustums of a cone are assembled by sharing the connection points; the number of sides of the annular tensegrity filled in the inner frustum of the designed area is determined by the number of frustums of a cone tangent to this frustum of a cone. The position of the outer end of the stabilizing rod is the position of the connection point, and the position of the inner ring node is further determined based on the position of the connection point.

[0047] In some preferred ways, the inner ring of the tensegrity is on the plane intercepted by the median line of the frustum of a cone. The radius r of the circumscribed circle of the inner ring node is obtained by multiplying the radius r' of the circle intercepted by the median line of the frustum of a cone by a reduction ratio k (0 < k < 1), that is, r = kr'. In Figure 6, taking the i-th frustum of a cone as an example, are the coordinate vectors of the center of the upper and lower bases of the frustum of a cone respectively, [[ID= sixteen]] are the upper and lower outer ends of the stabilizing rod corresponding to the j-th inner ring node N' required respectively,

[0048] , Figure 7 then the position vector of the j-th inner ring node of the i-th frustum of a cone is

[0048] As Figure 7As shown, because the frustum near the boundary curve only has connection points with the inner frustum, and no automatically generated connection points are present on the side close to the boundary curve, automatically filling the tensegrity module into the frustum will result in an incomplete module. In some preferred embodiments, the number of edges and node positions of the tensegrity structure filling the frustum at the boundary curve are determined by the number and positions of the connection points in the portion tangent to the inner frustum. The portion close to the boundary curve undergoes additional processing to increase the number of edges and determine the node positions of the annular tensegrity structure according to the principle of polygonal uniformity, thus forming a complete and stable module.

[0049] In some preferred embodiments, the structural system can be constructed in an assembled manner: first, the cross-sectional dimensions and cutting lengths of each component under zero stress are determined based on the form-finding and force-finding results of each tensegrity module, and the cutting is performed in the factory. The annular tensegrity modules are assembled and formed. The modules should be prestressed to ensure that the modules have a certain rigidity during transportation and installation. Secondly, the overall dome structure can be divided into several areas based on modules at the construction site. The modules in each area are connected on the ground according to the designed configuration, and then the areas are assembled and closed as a whole. Finally, after each module is installed in place, the vertical cables between the module connection points are tightened to apply prestress to the overall structure. The construction auxiliary facilities and the repeated vertical cables in the connection parts of the modules are removed, and the overall dome structure is completed.

[0050] Example 1

[0051] like Figure 8 、 9 As shown in Figures 10 and 10, with the parameters R = 10, H = 3.5, h = 1, and k = 0.8, a dome structure composed of seven infill circles on a spherical surface was designed as a specific embodiment of an annular tensegrity module. In this embodiment, the center circle is located at the center, and the remaining six circles are arranged annularly. The dome structure comprises 126 rod elements and 198 cable elements, resulting in a centrosymmetric structure.

[0052] Example 2

[0053] like Figure 11 、 12 As shown in Figure 13, parameters R = 10, H = 8, h = 0.8, and k = 0.7 were selected to design 36 infill circles on a spherical surface as a specific embodiment of a dome structure integrated with annular tensegrity modules. In this embodiment, the infill circles are asymmetrically distributed, and the overall dome structure includes 645 rod elements and 987 cable elements.

Claims

1. An assemblable dome structure integrated by annular tensegrity modules, characterized in that: The assemblable dome structure is obtained by assembling an N-gonal annular tensegrity structure in a grid-filled manner according to a plurality of circles on the surface of a sphere; The circular filling grid is distributed within the area enclosed by the boundary curve on the designed sphere with a radius R. It is based on a triangular grid. The centers of the filling circles in the circular filling grid are distributed at the vertices of the triangular grid, and the adjacent filling circles are tangent to the grid edges connected to the vertices of the triangular grid in which they are located. The three filling circles in any triangular grid are tangent to each other. All the filling circles are constrained by the boundary curve and the designed sphere, and together form a dense filling grid within the spherical area enclosed by the boundary curve. The N-gonal annular tensegrity structure comprises 3N nodes, N hoop rods, 2N stabilizers, 4N oblique cables, and N vertical cables; the N hoop rods are connected end to end to form a polygonal inner ring with a radius of r, and all the hoop rods are in the same plane; two stabilizers are connected to each node of the inner ring polygon, the outer endpoints of the two stabilizers are each connected to the adjacent nodes of the polygon via two oblique cables, and the outer endpoints of the two stabilizers are connected to each other via one vertical cable; the plane where the stabilizer connected to each node of the inner ring polygon lies is the normal plane of the polygon's circumcircle passing through the node; The filling circles distributed on the surface of the sphere are extruded along their circumference in the normal direction of the designed sphere with a thickness of h , forming a busbar l The frustum of the cone is extended and intersects with the center of the designed sphere. The upper and lower bases of all frustums are tangent to each other. The tangent points of the upper and lower bases of adjacent frustums serve as a pair of connection points between the frustums, and the extension lines of the lines connecting the pair of connection points converge at the center of the designed sphere; the three frustums on any triangular grid are connected in pairs through three pairs of connection points to form a stable triangulated assembly pattern, and all modules are assembled to the overall structure in this pattern.

2. The assemblable dome structure integrated by annular tensegrity modules according to claim 1, characterized in that: Filling the space of the truncated cone with an annular tensegrity module, placing the outer end points of the annular tensegrity stabilizer rods at the connection points, and assembling different modules through the shared connection points; The number of sides of the annular tensegrity that fills the inner frustum of the design area is determined by the number of frustums tangent to the frustum, and the position of each node is determined by the position of the connection point.

3. The assemblable dome structure integrated with annular tensegrity modules according to claim 1, characterized in that: The nodes are hinged nodes, and spherical joints are provided at all nodes, so that the rod units and the cable units can rotate at the nodes.

4. The assemblable dome structure integrated by annular tensegrity modules according to claim 1, characterized in that: The assembled dome structure is constructed in an assembly-based manner: first, the cross-sectional dimensions and cutting lengths of each component under zero stress are determined based on the form-finding and force-finding results of each tensegrity module. Cutting is then performed in a factory, and each annular tensegrity module is assembled and formed. Second, after each module is hoisted into place at the construction site, the vertical cables between the connection points of the tension modules are tightened to apply prestress to the overall structure. Once all modules are installed, the overall dome structure is completed.

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