A bidirectional beam string structure with rectangular plane

Abstract

The present invention discloses a bidirectional beam string structure of a rectangular plane, comprising: an upper beam system, a lower cable system and a strut; the upper beam system is composed of two groups of beam systems whose horizontal projections are orthogonal and upright, and the intersection of the two groups of beam systems forms an upper beam system node, and the horizontal projections of the two groups of beam systems are respectively parallel to the two opposite sides of the structural rectangular plane, and the beam end nodes and the upper beam system nodes are both located on an elliptical parabola; the lower cable system is composed of two groups of cable systems whose horizontal projections are oblique, and the horizontal projections of the two groups of cable systems are respectively parallel to the two diagonal directions of the structural rectangular plane, and the intersection of the two groups of cable systems forms a lower cable system node, and the lower cable system node coincides with the horizontal projection of the corresponding upper beam system node; the strut connects the lower cable system node and the corresponding upper beam system node. Each upper grid of the present invention is a plane quadrilateral, which reduces the difficulty of processing and installing the roof unit, and at the same time, the force efficiency of all the string cables is equivalent, which improves the stiffness and stability of the side beam string.

Description

Technical Field

[0001] The invention relates to the technical field of building engineering, in particular to a bidirectional beam string structure with a rectangular plane. Background Art

[0002] The string-type structure is composed of a rigid upper beam (system), a flexible lower cable (system) and a strut connecting the two. It is a typical hybrid structural system composed of rigid and flexible units. The earliest application form of this type of structural system is the plane-loaded beam string, in which the rigid part uses one-way components such as beams and arches, and the flexible part uses a single cable. Based on the beam string, different types have gradually developed, such as the string-type three-dimensional truss, the two-way beam string structure, the multi-directional beam string structure, and the string-type lattice shell.

[0003] In recent years, the string structure has been widely used in various large-span building roof structures due to its advantages such as large span capacity, superior force performance and good economy. In particular, the bidirectional string beam structure has been welcomed by architects and structural engineers in building structures such as skylights due to its transparent architectural effect and bidirectional force transmission advantages. Figure 1 shown.

[0004] When applied to large-span structures with rectangular planes, bidirectional beam string structures are usually composed of an orthogonal beam system, an orthogonal cable system that coincides with the horizontal projection of the beam system, and a strut connecting the two. Glass roofs or metal roofs are generally used. In engineering practice, the existing technology has two problems:

[0005] (1) When a bidirectional beam string structure is applied to a flat roof, the roof needs to have a certain slope to meet drainage requirements; when a unitized glass or metal roof is used, each upper structural grid should be a plane quadrilateral to avoid warping of the roof unit. If the structure is used to find the slope, the upper beam system needs to adopt a slightly convex surface or multiple planes spliced ​​together. In this case, it is usually impossible to ensure that each grid is a plane quadrilateral, which increases the difficulty of processing and installing the roof unit.

[0006] (2) The spans of the cables in the two directions of the orthogonal lower cable system are equal. For the side frame cables, their shape is restricted by the shape of the cables orthogonal to them. Usually, the vertical span ratio is small and the force efficiency is low. The cable system cannot fully play its role, resulting in low stiffness and stability of the structure at the side frame string beam.

[0007] The above problems have affected the economy and mechanical performance of the building structure to a certain extent, and increased the difficulty of applying the bidirectional beam-string structure in the rectangular plane large-span structure.

[0008] The information disclosed in this background technology section is only intended to deepen the understanding of the overall background technology of the present application, and should not be regarded as acknowledging or suggesting in any form that the information constitutes the prior art already known to those skilled in the art. Summary of the invention

[0009] The object of the present invention is to provide a bidirectional beam string structure with a rectangular plane to solve the technical problems existing in the prior art that the roof unit is difficult to process and install, and the side beam string has low stiffness and stability.

[0010] In order to achieve the above object, the present invention adopts the following technical solutions:

[0011] A bidirectional beam string structure of a rectangular plane, the structure comprising: an upper beam system, a lower cable system and a strut; wherein the upper beam system is formed by connecting two groups of beam systems whose horizontal projections are orthogonal and upright, the intersection of the two groups of beam systems forms an upper beam system node, the horizontal projections of the two groups of beam systems are respectively parallel to two groups of opposite sides of the structural rectangular plane, the beam end nodes and the upper beam system nodes are both located on an elliptical parabola, and the equation of the elliptical parabola is Where a and b are constants, x, y, and z are the coordinates of the beam end nodes and the upper beam system nodes in a three-dimensional coordinate system, the three-dimensional coordinate system takes the center of the rectangular plane roof as the origin, the x-axis and the y-axis are respectively parallel to the two opposite sides of the structural rectangular plane, and the z-axis is vertically upward;

[0012] The lower cable system is composed of two groups of cable systems whose horizontal projections are inclined. The horizontal projections of the two groups of cable systems are parallel to the two diagonal directions of the structural rectangular plane respectively. The intersection of the two groups of cable systems forms a lower cable system node. The lower cable system node coincides with the horizontal projection of the corresponding upper beam system node.

[0013] The brace is located between the upper beam system and the lower cable system, connecting the lower cable system node and the corresponding upper beam system node.

[0014] Furthermore, each of the lower layer cable system nodes is connected to the corresponding upper layer beam system node above it through the brace.

[0015] Furthermore, the elevation of the lower layer cable tie node is determined by form finding.

[0016] Compared with the prior art, the rectangular bidirectional beam string structure proposed in the present invention has two beneficial effects:

[0017] 1. The nodes of the upper beam system are positioned using elliptical paraboloid equations, and the horizontal projection of the quadrilateral grid formed by the intersection of the two sets of beam systems is a rectangle. This arrangement can make each upper grid a plane quadrilateral, and the structure itself has a smooth surface and a slope that can meet drainage requirements, which greatly facilitates the processing and installation of glass or metal unit roofs.

[0018] 2. The lower cable system is arranged obliquely, and the projections of the two groups of cable systems are parallel to the diagonals of the structural rectangular plane. For any group of cable systems, the cables close to the diagonal have a large span and a large sag, while the cables far from the diagonal have a small span and a small sag. Therefore, the sag-to-span ratios of all cables are close and the force efficiency is equivalent, so that the stiffness of the overall structure can be uniform. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0020] Figure 1 It is a schematic diagram of a bidirectional beam string structure in the prior art;

[0021] Figure 2 A schematic diagram of the upper beam system grid of the bidirectional beam string provided by the present invention;

[0022] Figure 3 An axonometric diagram of the bidirectional beam string structure provided in Example 1 of the present invention;

[0023] Figure 4 An exploded view of the bidirectional beam string structure provided in Example 1 of the present invention;

[0024] Figure 5 A plan view of a bidirectional beam string structure provided in Example 1 of the present invention;

[0025] Figure 6 for Figure 5 Cross-section of the structure of the middle P1 region;

[0026] Figure 7 for Figure 5 Cross-section of the structure of the P2 region;

[0027] Figure 8 An axonometric view of a bidirectional beam string structure provided in Example 2 of the present invention;

[0028] Fig. 9 An exploded view of a bidirectional beam string structure provided in Example 2 of the present invention;

[0029] Fig.10 A plan view of a bidirectional beam string structure provided in Example 2 of the present invention;

[0030] Fig.11 for Fig.10 Cross-section of the structure of the P3 region;

[0031] Fig.12 for Fig.10 Cross-section of the structure of the middle P4 region;

[0032] Among them: 101 is the upper beam system, 102 is the lower cable system, 103 is the strut, 201 is the beam end node, 202 is the upper beam system node, and 203 is the lower cable system node. DETAILED DESCRIPTION

[0033] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0034] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0035] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0036] The specific implementation of the present invention is described in detail below in conjunction with the accompanying drawings. It should be understood that the specific implementation described here is only used to illustrate and explain the present invention, and is not used to limit the present invention.

[0037] Embodiment 1

[0038] like Figure 2 , Figure 3 , Figure 4 , Figure 5 , Figure 6 and Figure 7The figure shows a first specific implementation of a rectangular bidirectional beam string structure of the present invention. In this embodiment, the bidirectional beam string structure is composed of an upper beam system 101, a lower cable system 102 and a strut 103, and the horizontal projection of the structure is a square.

[0039] The upper beam system 101 is composed of two beam systems with orthogonal horizontal projections. The horizontal projections of the two beam systems are parallel to the two opposite sides of the structural square plane. The beam end nodes 201 and the upper beam system nodes 202 are both located on the elliptical paraboloid. A three-dimensional coordinate system is established with the center of the rectangular plane roof as the origin. The x-axis and y-axis of the three-dimensional coordinate system are parallel to the two opposite sides of the structural square plane, and the z-axis is vertically upward. Then the equation of the elliptical paraboloid where the beam end nodes 201 and the upper beam system nodes 202 are located is: Where a and b are constants, and x, y, and z are the three-dimensional coordinates of the beam end node 201 and the upper beam system node 202;

[0040] All grids formed by the upper beam system 101 are plane quadrilaterals, as shown below:

[0041] Take any quadrilateral mesh (ref. Figure 2 ), the coordinates of the four corner points of the grid are A(x0,y0,z0), B(x0+L,y0,z1), C(x0+L,y0+W,z2), and D(x0,y0+W,z3). According to the surface equations of the beam end node 201 and the upper beam system node 202, the z coordinates of the four corner points can be divided into:

[0042]

[0043]

[0044]

[0045]

[0046] The vectors of the two sets of opposite sides of the grid are obtained as follows:

[0047]

[0048]

[0049] The above relationship shows that the two sets of opposite sides of the grid are parallel, so the four corner points of the grid are coplanar, that is, the grid is a planar quadrilateral.

[0050] The lower cable system 102 is composed of two groups of cable systems with orthogonal horizontal projections. The projections of the two groups of cable systems are parallel to the diagonal direction of the structural square plane, and intersect below the upper beam system node 202 to form a lower cable system node 203, that is, the lower cable system node 203 coincides with the horizontal projection of the corresponding upper beam system node 202. The elevation of the lower cable system node 203 is determined by form finding. The lower cable system 102 is fully distributed, that is, a brace 103 and a lower cable system 102 are provided below each upper beam system node 202.

[0051] The brace 103 is located between the upper beam system 101 and the lower cable system 102 , connecting the lower cable system node 203 and the corresponding upper beam system node 202 .

[0052] By adopting the above technical solution, this embodiment has the following advantages:

[0053] 1. The beam end node 201 and the upper beam system node 202 are positioned using elliptical paraboloid equations, and the horizontal projection of the quadrilateral grid formed by the intersection of the two sets of beam systems is a rectangle. This arrangement can make each upper grid a plane quadrilateral, and the structure itself has a smooth curved surface and a slope that can meet drainage requirements, thereby greatly facilitating the processing and installation of glass or metal unit roofs.

[0054] 2. The lower cable system 102 is arranged obliquely, and the projections of the two groups of cable systems are parallel to the diagonals of the structural rectangular plane. For any group of cable systems, the cables close to the diagonal have a large span and a large sag, and the cables far from the diagonal have a small span and a small sag. Therefore, the sag-to-span ratios of all cables are close and the force efficiency is equivalent, so that the stiffness of the overall structure can be uniform.

[0055] Embodiment 2

[0056] like Figure 8 , Fig. 9 , Fig.10 , Fig.11 and Fig.12 The figure shows a second specific implementation of a bidirectional beam string structure of a rectangular plane of the present invention. The arrangement of the bidirectional beam string structure in this embodiment is basically the same as that in the first embodiment, and the similarities are not repeated here. The difference compared with the first embodiment is that the horizontal projection of the structure is a rectangle, and the lower cable system 102 is arranged in a hollow manner, that is, along the direction parallel to the diagonal of the rectangular plane, a brace 103 and a lower cable system 102 are arranged below every other row of upper beam system nodes 202.

[0057] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A bidirectional beam string structure with a rectangular plane, the structure comprising: The upper layer beam system, the lower layer cable system and the struts; wherein the upper layer beam system is composed of two groups of beam systems whose horizontal projections are orthogonal and upright, the intersection of the two groups of beam systems forms an upper layer beam system node, the horizontal projections of the two groups of beam systems are respectively parallel to the two groups of opposite sides of the structural rectangular plane, the beam end nodes and the upper layer beam system nodes are both located on an elliptical parabola, and the elliptical parabola equation is ,in a , b is a constant, x , y , z are the coordinates of the beam end nodes and the upper beam system nodes in a three-dimensional coordinate system, where the origin is the center of the rectangular plane roof. x Axis and y The axes are parallel to two sets of opposite sides of the structural rectangular plane, z The axis is vertically upward; The lower cable system is composed of two groups of cable systems whose horizontal projections are inclined. The horizontal projections of the two groups of cable systems are parallel to the two diagonal directions of the structural rectangular plane respectively. The intersection of the two groups of cable systems forms a lower cable system node. The lower cable system node coincides with the horizontal projection of the corresponding upper beam system node. The brace is located between the upper beam system and the lower cable system, connecting the lower cable system node and the corresponding upper beam system node; The lower cable system is arranged in a hollow manner, that is, struts and lower cable systems are arranged below every other row of upper beam system nodes in a direction parallel to the diagonal of the rectangular plane.

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