A rib-ring type foldable scissor cable dome structure

Abstract

The application discloses a rib-ring type foldable shear-type cable dome structure, which comprises m rings, n identical shear-type trusses, each of which comprises m shear-type units, wherein m and n are natural numbers and m is greater than or equal to 2 and n is greater than or equal to 3. The structure comprises 3m*n+2 nodes, m*n shear-type units, 2m*n rod members and 2m ring cables in total. In the application, the shear-type unit system replaces the original strut system, and is combined with the tensioning action of the ring cable to effectively realize the folding and unfolding control of the rib-ring type cable dome, and the radial stability of the structure is greatly improved, and the anti-collapse performance is also significantly improved. In the construction and installation process, the construction cost and difficulty can be reduced, manpower and material resources can be saved, and construction safety can be ensured.

Description

Technical Field

[0001] This invention relates to a rib-ring type foldable and deployable cable dome structure. Background Technology

[0002] With the advancement of technology and the improvement of people's living standards, society has a wider demand for various large-scale public buildings, and structural designs that are rationally stressed, lightweight, and economical in cost are becoming increasingly popular. Flexible cable structures, which are rigidified by applying prestress, are rationally stressed and highly efficient. When combined with other rigid structures, they can meet various requirements in working conditions, thus gaining wider and wider application.

[0003] Currently, conventional cable domes suffer from high construction difficulty, uneconomical cost, and excessively high technical requirements for opening and closing control. However, deployable structures are widely applicable to various temporary buildings, are easy to disassemble and reuse multiple times, and have the potential for parameter adjustment according to application scenarios. Therefore, endowing large-span structures, such as cable domes, with deployable characteristics has broad application prospects. Furthermore, replacing the struts of cable domes with scissor hinges, a classic deployable component, can enhance the overall performance of cable dome structures. Therefore, those skilled in the art need to optimize the opening and closing control of cable domes using scissor hinges to address the current problems of high construction difficulty, uneconomical cost, and excessively high technical requirements for opening and closing control in conventional cable domes. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a novel foldable and deployable cable dome structure with advantages such as self-balancing and disassembly, which can be widely used in various temporary buildings.

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

[0006] A rib-ring type foldable scissor-type cable dome structure is disclosed. The projected shape of the cable dome structure consists of m closed loops of unequal size, all with their centroids at the same point, where m and n are natural numbers, and m ≥ 2 and n ≥ 3. The structure comprises one retractable central strut and n scissor trusses, each scissor truss consisting of m scissor units hinged end-to-end. The structure includes two nodes above and below the central strut, 3m*n nodes hinged together by scissor members, and 2m*n circumferential cables.

[0007] Furthermore, this structure can be fully folded but does not meet the condition for full deployment. When the structure is deployed to the designed deployment state, the stress of the ring cables and the remaining members reaches a self-equilibrium state. The geometric condition that the length of each member of the scissor unit in each scissor truss must satisfy is: in two adjacent scissor units, the sum of the lengths of the two members of the first scissor unit hinged to the side of the second scissor unit is equal to the sum of the lengths of the two members of the second scissor unit hinged to the side of the first scissor unit.

[0008] Furthermore, this structure controls the distance between the upper and lower nodes of the center by adjusting the length of the telescopic central rod, thereby driving the expansion and contraction of the scissor truss to achieve the overall structure's folding and unfolding.

[0009] Furthermore, the two central nodes of the cable dome structure are connected to a telescopic central rod. When the length of the telescopic central rod reaches the minimum design length, the overall structure reaches the designed unfolded state. When the length of the telescopic central rod reaches the maximum design length, the overall structure is fully folded.

[0010] Furthermore, apart from the two nodes connecting the central rod, the horizontal projections of the remaining 3m*n nodes form the vertices of each regular n-sided ring. These can be divided into upper chord hinge points, lower chord hinge points, and inner hinge points. When this structure is unfolded to the designed unfolded state, the height of the upper chord node on the same frame changes with the lateral distance from the center point according to a certain assumed function relationship, and the line connecting the upper and lower chord hinge points on the same side of the same scissor unit remains perpendicular to the horizontal plane during the unfolding process.

[0011] Furthermore, the cable dome structure includes a cable dome, which includes 2m×n circumferential cables. Each ring has 2n cables of the same length. The topological relationship is as follows: two cables form a group, which sequentially cross and connect the four upper and lower chord nodes of two adjacent frames in each ring. Each ring has n groups of cables connected in the above manner, and all cables in the same ring have the same length.

[0012] Furthermore, during the unfolding process of the cable dome structure, the ring cables gradually tighten, reaching the design prestress when the structure reaches the designed unfolded state. During the folding process, the ring cables gradually relax, and the stress of the ring cables is zero when the structure is fully folded.

[0013] All nodes are hinged nodes, and the rod and cable units are only subjected to axial forces from the nodes; all scissor rods in the structure have preload, all cables have preload, and the overall structure satisfies prestress self-balancing.

[0014] The beneficial effects of this invention are:

[0015] (1) In this invention, the scissor unit system replaces the original strut system. That is, the radial scissor unit group can be regarded as a group of continuously variable struts. The height of the struts can be adjusted. With the tensioning effect of the ring cable, the folding and unfolding control of the rib ring cable dome can be effectively realized. Compared with the traditional pure rigid deployable structure, such as the retractable roof, the addition of the flexible structure system represented by the cable makes the folding and unfolding of the structure easier to control.

[0016] (2) Compared with the traditional single strut system, the scissor strut system greatly improves the radial stability of the strut. At the same time, setting two intersecting continuous ring cables in the same ring can better balance the circumferential pressure, which significantly improves the collapse resistance of the structure.

[0017] (3) This structure can be installed and connected with all scissor units and ring cables when fully folded. Then, the structure can be unfolded and controlled by controlling the hydraulic rods to generate prestressed stiffness. This can avoid high-altitude operations and temporary scaffolding installation during construction, reduce construction costs and difficulties, save manpower and resources, and ensure construction safety. Attached Figure Description

[0018] Figure 1 This is a top view of the invention when it reaches its designed unfolded state.

[0019] Figure 2 This is a side view of the invention when it reaches the designed unfolded state.

[0020] Figure 3 This is a perspective view of the invention in its designed unfolded state.

[0021] Figure 4 This is a schematic diagram of the node numbering of the present invention.

[0022] Figure 5 This is a schematic diagram of the index number of the present invention.

[0023] Figure 6 This is a schematic diagram of the design parameters and rod unit of the single scissor truss of the present invention.

[0024] Figure 7 This is a schematic diagram of the retractable rod at the center of the dome structure in this invention.

[0025] Figure 8 In Example 1, n = 6, m = 3, x i =15i, h0=h1=4, target curve relationship A three-dimensional image of the time.

[0026] Figure 9 In Example 1, n = 6, m = 3, x i =15i, h0=h1=4, target curve relationship A schematic diagram of the folding process.

[0027] Figure 10 In Example 2, n = 8, m = 4, x i =10i, h0=h1=4, target curve relationship x 2 +(z-50.5) 2 =50.5 2 A three-dimensional image of the time.

[0028] Figure 11 In Example 2, n = 8, m = 4, x i =10i, h0=h1=4, target curve relationship x 2 +(z-50.5) 2 =50.5 2 A schematic diagram of the folding process. Detailed Implementation

[0029] To make the objectives, structural form, and advantages of this application clearer, the application is described and illustrated below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application. All other embodiments obtained by those skilled in the art based on the embodiments provided in this application without inventive effort are within the scope of protection of this application.

[0030] like Figure 1 , 2 As shown in Figure 3, this invention provides a rib-ring type foldable scissor-type cable dome structure. The projected shape of the cable dome structure is a regular n-gon, which can be divided into m rings, where m and n are natural numbers and m≥2, n≥3. In this document, m and n have no meaning and only represent the number. This structure consists of one retractable central rod 1 and n identical scissor trusses, where each scissor truss is composed of m scissor units that are sequentially hinged end to end. This structure includes two nodes above and below the central rod and 3m*n nodes that are hinged to each other by scissor members 2. These hinge points can be divided into upper chord hinge points 3, lower chord hinge points 4, and inner hinge points 5 according to their positions within the truss. The line connecting the upper and lower chord hinge points on the same side of each scissor unit remains perpendicular to the horizontal plane throughout the folding and unfolding process. When the structure is unfolded to the designed unfolded state, the height of the upper chord node on the same truss changes with the lateral distance from the center point according to a certain design function. Each scissor truss can be fully folded but does not meet the conditions for full unfolding. The relationship that the lengths of each member must satisfy will be introduced below.

[0031] like Figure 4 As shown, except for the two nodes above and below the central member, each hinge point of each scissor truss is named... i = 1, 2, ..., 3m, j = 1, 2, ..., n. When i ∈ [1, m], the node is the upper chord hinge point; when i ∈ [m+1, 2m], the node is the lower chord hinge point; when i ∈ [2m+1, 3m], the node is the inner hinge point. The superscript j indicates the number of the truss where the hinge point is located.

[0032] The upper and lower nodes of the central member are the connection points of each truss. The upper node is named N0, and the lower node is named N′0. The upper node is the origin of the coordinate system, and the straight line containing the central telescopic member is the z-axis. The hinge points of the scissor truss are also considered. Coordinates are These nodes are connected to the ring cable 6, as shown. Figure 5 As shown.

[0033] like Figure 6 As shown, one of the scissor trusses is defined as the first scissor truss, and the plane containing this truss is the xoz plane. The nodes of the first truss... Coordinates are i = 1, 2, ..., 3m. Given the target curve z = f(x) fitted to the upper chord nodes of the truss, the truss can be uniquely determined by the following independent design parameters: the number of scissor elements m, and the distance x between each upper chord node and the central telescopic member. i Let i = 1, 2, ..., m. When expanded to the design state, the height difference h0 between the upper and lower nodes of the central rod (h0 = z0 - z′0) is equal to the height difference h1 between the upper and lower chord nodes closest to the central rod. The functional relationship z = f(x) determines the shape of the truss when the invention is fully deployed. This is achieved by adjusting the parameter x. i Different values ​​of h0 and h1 can determine the span-to-height ratio, the length of each member, and the position of each node of the truss when the invention is fully deployed. Each scissor unit can be divided into four members by the hinge joint, each member having a length of a. ij , i=1,2,…m, j=1,2,…4.

[0034] Based on the fact that the upper chord node is located on the target curve z = f(x):

[0035]

[0036] Based on the fact that the line connecting the upper and lower chord nodes is perpendicular to the horizontal plane:

[0037] x i =x i+m ,i=1,2,…m (2)

[0038] From (2), we can infer that geometric similarity means:

[0039] a i1 *a i4 =a i2 *a i3 ,i=1,2,…m (3)

[0040] To satisfy the condition of complete folding, the following must be met:

[0041] a i3 +a i4 =a (i+1)1 +a (i+1)2 ,i=1,2,…m-1 (4)

[0042] The length a of the first shear unit member can be obtained from the initial parameters h0, h1 and (1)(2)(3).13 and a 14 and center hinge point From (4), we know that a 21 +a 22 =a 13 +a 14 Substituting into (1), (2), and (3), we can obtain the length of the second scissor unit member and the center hinge point. and the bottom string point The coordinates of the members can be used to calculate the lengths and coordinates of all members within the truss.

[0043] like Figure 4 As shown, the horizontal projection points of each node of the cable dome structure are the vertices of a regular n-gon. Parameter n and the design parameters of the scissor truss constitute the design parameters of this invention. The j-th scissor truss can be considered as the first scissor truss rotated counterclockwise around the z-axis by 2(j-1)π / n. Let α = 2π / n, the coordinates of each node of the other trusses can be obtained from the coordinates of the nodes of the first scissor truss, as follows:

[0044]

[0045] like Figure 4 As shown, in some preferred embodiments, the loop cables are interconnected with the upper and lower chord nodes of the scissor truss, and the topological connection of the loop cables is as follows:

[0046] and Connecting ring cable and Connecting ring cable

[0047] and Connecting ring cable and Ring cable

[0048] and Connecting ring cable and Connecting ring cable

[0049] and Connecting ring cable and Connecting ring cable

[0050] Where i = 1, 2, ..., m; j = 1, 2, ..., n

[0051] There are a total of 2m*n ring cables, of which the ring cables and ring cable The two lines intersect each other, and their horizontal projections coincide to form a straight line. When j is traversed sequentially in [1, n], the loop... and ring cable The horizontal projection of the object is a closed loop of a regular n-sided polygon, each loop containing 2n loops of equal length. The projection of all the loops is m closed loops of regular n-sided polygons of unequal size, with their centroids at the same point.

[0052] The length of the loop cable is:

[0053]

[0054] Figure 7 This is a schematic diagram of the central telescopic rod of the present invention. By adjusting the length of the telescopic central rod, the distance between the upper and lower nodes of the center is controlled, thereby driving the expansion and contraction of the scissor truss to achieve the folding and unfolding of the overall structure. Specifically, it includes the following steps:

[0055] (1) Fix the central telescopic rod and its length in a preferred manner.

[0056] (2) Adjust the tension of each ring cable in a preferred manner step by step to relax or tension it to the design prestress.

[0057] (3) The length of the central telescopic rod is adjusted in a preferred manner. When the structure is deployed, the length of the central telescopic rod is adjusted to the minimum length h0, and when the structure is deployed, the length of the central telescopic rod is adjusted to the maximum length a. 11 +a 12 .

[0058] The installation of this invention's structure in a fully folded state offers significant advantages over traditional rib-ring structure construction methods. The specific installation process is as follows:

[0059] (1) Install the outer ring beam around the perimeter.

[0060] (2) Pre-assemble each scissor truss and connect each ring cable to the truss in a preferred manner.

[0061] (3) Adjust each scissor truss and connect it to both ends of the central telescopic rod and the outer ring beam in sequence.

[0062] (4) Adjust the length of the central telescopic rod in a preferred manner, adjusting the rod length to the designed length a when fully folded. 11 +a 12 .

[0063] At this point, the installation of the invention is complete in its fully folded state.

[0064] Example 1

[0065] like Figure 8 As shown, the following parameters are selected: n = 6, m = 3, x i =15i, h0=h1=4, target curve relationship As a specific embodiment of a rib-ring type foldable and deployable cable dome structure, this structure is designed to unfold into a parabolic shape, and the folding process is as follows: Figure 9 As shown.

[0066] Example 2 Figure 10 As shown, the following parameters are selected: n = 8, m = 4, x i =10i, h0=h1=4, target curve relationship x 2 +(z-50.5) 2 =50.5 2 As a specific embodiment of a rib-ring type foldable and deployable cable dome structure, the structure is designed to have a spherical shape when unfolded, and the folding process is as follows: Figure 11 As shown.

[0067] Those skilled in the art should understand that the technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments have been described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0068] The embodiments described above are merely examples of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application.

Claims

1. A rib-ring type foldable and deployable cable dome structure, characterized in that, The projected shape of the cable dome structure is m closed loops of unequal size, all with their centroids at the same point, where m and n are natural numbers and m ≥ 2 and n ≥ 3. The cable dome structure includes one retractable central strut and n scissor truss assemblies, each scissor truss consisting of m scissor units hinged end-to-end. The nodes of the cable dome structure include two central nodes (top and bottom) and 3m × n nodes hinged together by scissor members. The two central nodes of the cable dome structure are respectively connected to the retractable central strut. When the length of the telescopic center rod reaches the minimum design length, the overall structure reaches the designed unfolded state. When the length of the telescopic center rod reaches the maximum design length, the overall structure is fully folded. The cable dome structure includes a cable dome, which includes 2m×n circumferential cables. Each ring has 2n ring cables of the same length. The topological relationship is as follows: two ring cables form a group, which are sequentially and crosswise connected to the four upper and lower chord nodes of two adjacent frames in each ring. Each ring has n groups of ring cables connected in the above manner. All ring cables in the same ring have the same length.

2. The rib-ring type foldable and deployable cable dome structure according to claim 1, characterized in that, In each scissor truss, the length of each member of the scissor unit must meet the condition of complete folding, that is: in two adjacent scissor units, the sum of the lengths of the two members of the first scissor unit hinged to the side of the second scissor unit is equal to the sum of the lengths of the two members of the second scissor unit hinged to the side of the first scissor unit.

3. A rib-ring type foldable and deployable cable dome structure according to claim 1 or 2, characterized in that, During the unfolding process, the ring cables of the cable dome structure gradually tighten, reaching the design prestress when the structure reaches the designed unfolded state. During the folding process, the ring cables gradually relax, and the stress of the ring cables is zero when the structure is fully folded.

Images