阅读说明：本技术 一种矩形平面的双向张弦梁结构 (Bidirectional beam string structure with rectangular plane ) 是由 白光波 朱忠义 王昕� 周忠发 于 2021-08-17 设计创作，主要内容包括：本发明公开了一种矩形平面的双向张弦梁结构,包括：上层梁系、下层索系和撑杆；上层梁系由水平投影为正交正放的两组梁系连接构成,两组梁系相交处形成上层梁系节点,两组梁系的水平投影分别平行于结构矩形平面的两组对边,梁端节点和上层梁系节点均位于椭圆抛物面上；下层索系由水平投影为斜放的两组索系组成,两组索系的水平投影分别与结构矩形平面的两个对角线方向平行,两组索系相交处形成下层索系节点,下层索系节点与对应的上层梁系节点的水平投影重合；撑杆连接下层索系节点和相应的上层梁系节点。本发明的每个上层网格均为平面四边形,降低了屋面单元加工和安装难度,同时所有张弦索的受力效率相当,提高了边榀张弦梁的刚度和稳定性。(The invention discloses a bidirectional beam string structure with a rectangular plane, which comprises: an upper layer beam system, a lower layer cable system and a support rod; the upper beam system is formed by connecting two groups of beam systems with orthogonal and orthographic horizontal projections, upper beam system nodes are formed at the intersection of the two groups of beam systems, the horizontal projections of the two groups of beam systems are respectively parallel to two groups of opposite sides of the rectangular plane of the structure, and the beam end nodes and the upper beam system nodes are both positioned on the elliptic paraboloids; the lower-layer cable system consists of two groups of cable systems with inclined horizontal projections, the horizontal projections of the two groups of cable systems are respectively parallel to two diagonal directions of a structural rectangular plane, a lower-layer cable system node is formed at the intersection of the two groups of cable systems, and the lower-layer cable system node is superposed with the horizontal projection of the corresponding upper-layer beam system node; the brace rod is connected with the lower layer cable system node and the corresponding upper layer beam system node. Each upper grid of the invention is a plane quadrangle, thereby reducing the processing and installation difficulty of the roof unit, simultaneously the stress efficiency of all the beam strings is equivalent, and the rigidity and stability of the side beam string beams are improved.)

1. A rectangular planar bidirectional beam string structure, comprising: an upper layer beam system, a lower layer cable system and a support rod; the beam system is characterized in that the upper-layer beam system is formed by connecting two groups of beam systems with orthogonal horizontal projections, upper-layer beam system nodes are formed at the intersection of the two groups of beam systems, the horizontal projections of the two groups of beam systems are respectively parallel to two opposite sides of a rectangular plane of the structure, the beam end nodes and the upper-layer beam system nodes are both positioned on an elliptic paraboloid, and the elliptic paraboloid equation is thatA and b are constants, x, y and z are coordinates of beam end nodes and upper beam system nodes under a three-dimensional coordinate system, the three-dimensional coordinate system takes the center of a rectangular plane roof as an origin, an x axis and a y axis are respectively parallel to two groups of opposite sides of the rectangular plane of the structure, and the z axis is vertically upward;

the lower-layer cable system consists of two groups of cable systems with inclined horizontal projections, the horizontal projections of the two groups of cable systems are respectively parallel to two diagonal directions of a structural rectangular plane, a lower-layer cable system node is formed at the intersection of the two groups of cable systems, and the horizontal projection of the lower-layer cable system node is superposed with the horizontal projection of the corresponding upper-layer beam system node;

the support rods are positioned between the upper-layer beam system and the lower-layer cable system and are used for connecting lower-layer cable system nodes and corresponding upper-layer beam system nodes.

2. The rectangular planar bi-directional beam string structure of claim 1 wherein each said lower tier lashing node is connected to a corresponding said upper tier lashing node above it by said brace.

3. The rectangular planar bi-directional beam string structure of claim 1 wherein the elevation of said underlying lashing node is determined by form-finding.

Technical Field

The invention relates to the technical field of constructional engineering, in particular to a bidirectional beam string structure with a rectangular plane.

Background

The string structure is composed of a rigid upper layer beam (system), a flexible lower layer cable (system) and a brace rod for connecting the rigid upper layer beam (system) and the flexible lower layer cable (system) and is a typical hybrid structure system composed of rigid units and flexible units. The earliest application form of such structural systems was a plane stressed beam string, the rigid part of which was a unidirectional member such as a beam or an arch, and the flexible part was a single cable. On the basis of beam string, different types such as beam string three-dimensional truss, bidirectional beam string structure, multidirectional beam string structure, beam string reticulated shell and the like are gradually developed.

In recent years, the string structure has the advantages of large spanning capability, excellent stress performance, good economy and the like, and is widely applied to various large-span building roof structures, particularly to a bidirectional string beam structure, which is welcomed by architects and structural engineers in building structures such as a daylighting roof and the like due to the advantages of transparent building effect and bidirectional force transmission, as shown in fig. 1.

When applied to a large-span structure with a rectangular plane, the bidirectional beam string structure generally consists of an orthogonal beam system, an orthogonal cable system superposed with the horizontal projection of the beam system and a brace rod connecting the two, and generally adopts a glass roof or a metal roof. In engineering practice, the prior art has two problems:

(1) when the bidirectional beam string structure is applied to a flat roof, the roof is required to have a certain gradient in order to meet the drainage requirement; when the unit type glass or metal roof is adopted, each upper layer structure grid is preferably a plane quadrangle, so that the warping of the roof unit is avoided. If the slope is found through the structure, the upper beam system needs to adopt a slightly convex curved surface or a splicing form of a plurality of planes, and under the condition, each grid cannot be guaranteed to be a plane quadrangle generally, so that the processing and installation difficulty of the roof unit is increased.

(2) The span of the guy cable in two directions of the orthogonal lower layer guy cable system is respectively equal, the shape of the side guy cable is limited by the position of the guy cable orthogonal to the side guy cable, the vertical span ratio is small, the stress efficiency is not high, the function of the guy cable system cannot be fully exerted, and the rigidity and the stability of the structure at the side guy beam are low.

The problems influence the economical efficiency and the stress performance of the building structure to a certain extent, and increase the application difficulty of the bidirectional beam string structure in a rectangular plane large-span structure.

The information disclosed in this background section is only for enhancement of understanding of the general background of the application and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.

Disclosure of Invention

The invention aims to provide a bidirectional beam string structure with a rectangular plane, and aims to solve the technical problems that a roof unit is difficult to process and install, and the rigidity and stability of a beam string at one side are low in the prior art.

In order to achieve the purpose, the invention adopts the following technical scheme:

a rectangular planar bidirectional beam string structure, comprising: an upper layer beam system, a lower layer cable system and a support rod; the upper-layer beam system is formed by connecting two groups of beam systems with orthogonal horizontal projections, upper-layer beam system nodes are formed at the intersection of the two groups of beam systems, the horizontal projections of the two groups of beam systems are respectively parallel to two groups of opposite sides of a rectangular plane of the structure, the beam end nodes and the upper-layer beam system nodes are both positioned on an elliptic paraboloid, and the elliptic paraboloid equation is thatA and b are constants, x, y and z are coordinates of beam end nodes and upper beam system nodes under a three-dimensional coordinate system, the three-dimensional coordinate system takes the center of a rectangular plane roof as an origin, an x axis and a y axis are respectively parallel to two groups of opposite sides of the rectangular plane of the structure, and the z axis is vertically upward;

the lower-layer cable system consists of two groups of cable systems with inclined horizontal projections, the horizontal projections of the two groups of cable systems are respectively parallel to two diagonal directions of a structural rectangular plane, a lower-layer cable system node is formed at the intersection of the two groups of cable systems, and the horizontal projection of the lower-layer cable system node is superposed with the horizontal projection of the corresponding upper-layer beam system node;

the support rods are positioned between the upper-layer beam system and the lower-layer cable system and are used for connecting lower-layer cable system nodes and corresponding upper-layer beam system nodes.

Furthermore, each lower layer cable tie node is connected with the corresponding upper layer beam tie node above the lower layer cable tie node through the support rod.

Furthermore, the elevation of the lower-layer cable system node is determined by shape finding.

Compared with the prior art, the bidirectional beam string structure with the rectangular plane has the beneficial effects of two aspects:

1. the upper beam system nodes are positioned by adopting an elliptic paraboloid equation, the horizontal projection of the quadrilateral grids formed by the intersection of the two sets of beam systems is rectangular, each upper grid can be a plane quadrilateral due to the arrangement mode, the curved surface of the structure is smooth, and the slope can meet the drainage requirement, so that the processing and the installation of glass or metal unit roofs are greatly facilitated.

2. The lower cable system is arranged obliquely, the projections of the two cable systems are respectively parallel to the diagonal line of the rectangular plane of the structure, for any one cable system, the cable span close to the diagonal line is large, the sag is large, the cable span far away from the diagonal line is small, and the sag is small, so that the sag ratios of all cables are close, the stress efficiency is equivalent, and the uniform rigidity of the whole structure can be realized.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and other drawings can be obtained by those skilled in the art without creative efforts.

FIG. 1 is a schematic diagram of a two-way beam string structure in the prior art;

FIG. 2 is a schematic diagram of an upper beam system grid of a two-way beam string provided by the present invention;

FIG. 3 is an isometric view of a bi-directional beam string structure provided in accordance with an embodiment of the present invention;

FIG. 4 is an exploded view of a bi-directional beam string structure according to an embodiment of the present invention;

FIG. 5 is a plan view of a two-way beam string structure provided in accordance with an embodiment of the present invention;

FIG. 6 is a cross-sectional view of the structure of the region P1 in FIG. 5;

FIG. 7 is a cross-sectional view of the structure of the region P2 in FIG. 5;

FIG. 8 is an isometric view of a two-way beam string structure provided in accordance with a second embodiment of the present invention;

fig. 9 is an exploded view of a two-way beam string structure provided in the second embodiment of the present invention;

fig. 10 is a plan view of a two-way beam string structure provided in the second embodiment of the present invention;

FIG. 11 is a cross-sectional view of the structure of the region P3 in FIG. 10;

FIG. 12 is a cross-sectional view of the structure of the region P4 in FIG. 10;

wherein: 101 is an upper beam system, 102 is a lower cable system, 103 is a brace rod, 201 is a beam end node, 202 is an upper beam system node, and 203 is a lower cable system node.

Detailed Description

The technical solutions of the present invention will be described clearly and completely with reference to the accompanying drawings, and it should be understood that the described embodiments are some, but not all embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplicity of description, but do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

The following detailed description of embodiments of the invention refers to the accompanying drawings. It should be understood that the detailed description and specific examples, while indicating the present invention, are given by way of illustration and explanation only, not limitation.

Example one

Referring to fig. 2, 3, 4, 5, 6 and 7, a first embodiment of a bidirectional beam string structure with a rectangular plane according to the present invention is shown, in this embodiment, the bidirectional beam string structure is composed of an upper beam system 101, a lower beam system 102 and a brace 103, and the horizontal projection of the structure is a square.

The upper beam system 101 is composed of two sets of beam systems with orthogonal horizontal projections, the horizontal projections of the two sets of beam systems are respectively parallel to two sets of opposite sides of a square plane of the structure, and the beam end node 201 and the upper beam system node 202 are both positioned on the elliptic paraboloid. A three-dimensional coordinate system is established by taking the center of the rectangular plane roof as an original point, the x axis and the y axis of the three-dimensional coordinate system are respectively parallel to two opposite sides of the square plane of the structure, the z axis is vertically upward, and then the equation of the elliptic paraboloids of the beam end nodes 201 and the upper-layer beam system nodes 202 isWherein a and b are constants, and x, y and z are three-dimensional coordinates of a beam end node 201 and an upper-layer beam system node 202;

each grid formed by the upper beam system 101 is a planar quadrilateral, which proves as follows:

arbitrarily take a quadrilateral mesh (refer to fig. 2), coordinates of four corner points of the mesh are respectively A (x)₀,y₀,z₀)、B(x₀+L,y₀,z₁)、C(x₀+L,y₀+W,z₂)、D(x₀,y₀+W,z₃) Then, according to the surface equation where the beam end node 201 and the upper beam system node 202 are located, the z-coordinate of the four corner points can be obtained as:

thus, the vectors of two groups of opposite sides of the grid are respectively:

the above relationship indicates that two sets of opposite sides of the grid are respectively parallel, so that four corner points of the grid are coplanar, namely the grid is a plane quadrangle.

The lower cable system 102 is composed of two cable systems with orthogonal and oblique horizontal projections, the projections of the two cable systems are respectively parallel to the diagonal direction of the square plane of the structure, and intersect below the upper beam system node 202 to form a lower cable system node 203, namely, the horizontal projection of the lower cable system node 203 and the corresponding upper beam system node 202 are overlapped. The elevation of the lower mooring node 203 is determined by form finding. The lower cable system 102 is fully distributed, that is, a stay bar 103 and the lower cable system 102 are arranged below each upper beam system node 202.

Brace 103 is located between upper tier beam system 101 and lower tier cable system 102, connecting lower tier cable system node 203 to corresponding upper tier beam system node 202.

By adopting the technical scheme, the embodiment has the following advantages:

1. the beam end nodes 201 and the upper beam system nodes 202 are positioned by adopting an elliptic paraboloid equation, the horizontal projection of the quadrilateral grids formed by the intersection of the two groups of beam systems is rectangular, each upper grid can be a plane quadrilateral due to the arrangement mode, the curved surface of the structure is smooth, and the slope can meet the drainage requirement, so that the processing and the installation of glass or metal unit roofs are greatly facilitated.

2. The lower-layer cable system 102 is arranged obliquely, projections of the two groups of cable systems are respectively parallel to a diagonal line of a rectangular plane of the structure, for any group of cable systems, the cable span close to the diagonal line is large, the sag is large, the cable span far away from the diagonal line is small, and the sag is small, so that the sag ratios of all cables are close, the stress efficiency is equivalent, and the uniform rigidity of the whole structure can be realized.

Example two

As shown in fig. 8, 9, 10, 11 and 12, a second embodiment of a two-way beam structure with a rectangular plane according to the present invention is shown, the arrangement of the two-way beam structure in this embodiment is substantially the same as that in the first embodiment, and the same points are not repeated herein, but the difference from the first embodiment is that the horizontal projection of the structure is rectangular, and the lower cable system 102 is arranged in an evacuation arrangement, that is, the bracing rods 103 and the lower cable system 102 are arranged below every other row of upper beam system nodes 202 along the direction parallel to the diagonal of the rectangular plane.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; while the invention has been described in detail and with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention.