JPH11124942A - Space truss structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To achieve junctions in a space truss structure which forms networks by the assembly of truss frames each having curved surfaces which differ in curvature in two directions, without causing twisting of the truss frames, and to make the three-dimensional truss structure applicable to even a large-scale structure of great load by use of chords and web members that are excellent in cross-section performance. SOLUTION: Truss frame members 1, each formed by connecting upper and lower chords 2, 3 together via a web member 4, and truss node parts 5 where the ends of the truss frames 1 are joined together are used to form a network through the assembly of the truss frames which differ in curvature in two directions. Then, a drawing point at the truss node part 5 of each diagonal 1B involved in the truss frame members 1 is placed in a position slightly deviating from the center of the truss node part so that the diagonals 1B are not twisted and so that the diagonals 1B are placed straight.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a long-span truss structure applied to a gymnasium, an event hall, and the like, and relates to a three-dimensional truss structure which forms a mesh by assembling truss frames having different curvatures in two directions. It is.

[0002]

2. Description of the Related Art A truss frame member formed by connecting upper and lower chord members via a web member and a truss node to which the ends of the truss frame member are joined are formed in a triangular or rhombic shape. In a three-dimensional truss structure that forms a mesh by assembling a truss frame member such as the one described above, it is general that the point of attraction of the chord gauge line at the truss joint is one point.

If the curved surface of the structure has a constant curvature like a spherical surface, there is no problem even if the attracting point is set to one point as described above, but if the curved surface of the structure has different curvatures in two directions. Has a problem that the truss frame material is twisted.

FIG. 5 (a) is a perspective view schematically showing the truss frame member 1 and the truss node 5 and the like by dots and lines. In the case of a curved surface having a constant radius of curvature R _A (shown by a solid line). Since the central axes of the bundles 7 of the adjacent truss node portions 5 are in the same plane, the horizontal member 1A and the diagonal member 1B of the truss frame member 1 are not twisted, but have different radii of curvature in two directions. R _a, in the case of a curved surface having a R _B (shown in dotted lines), the central axis of the bundle member 7 of the truss node portion 5 adjacent in the direction of the radius of curvature R _B is not located in the same plane, the slant member 1B Will be twisted.

In such a case, conventionally, an L-shaped steel member having low torsional rigidity is used for the upper chord, the lower chord, and the abdominal material, and the L-shaped steel member is twisted and attached on site. However, since the L-section steel (angle iron) member has relatively poor cross-sectional performance, it is good for a small-scale structure with a small load, but is good for a large-scale structure with a large load. Since it is necessary to use a member having high torsional rigidity such as a CT steel or an H-shaped steel for the chord material, it has been difficult to mount the string material.

The present invention has been developed in view of the above circumstances, and in a three-dimensional truss structure in which a mesh is formed by assembling a truss frame member having curved surfaces having different curvatures in two directions, the truss frame member is twisted. Provides a three-dimensional truss structure that can be joined without causing it, and can be applied to large-scale structures with large load using chords and webs with high torsional rigidity and excellent cross-sectional performance It is intended to be.

[0007]

In order to achieve the above-mentioned object, according to the present invention, a truss frame member formed by connecting upper and lower chord members via a belly member and an end of the truss frame member are joined. With the truss joints, in a three-dimensional truss structure that forms a mesh by assembling truss frames having different curvatures in two directions, attraction points at the truss joints of the diagonally arranged oblique members of the truss frames. The truss members are slightly offset from the center of the truss joints so that the slant members are not twisted.

In the case of a three-dimensional truss structure in which a mesh is formed by assembling truss frame members having different curvatures in two directions, FIG.
As shown by the dotted line in (a), if the central axes of the bundles of the adjacent truss nodes are not located in the same plane and the diagonal members are arranged as they are, each diagonal member is twisted. Therefore, FIG.
As shown in (b), if the pulling point at the truss node of the diagonal material is slightly shifted from the center of the truss node so as to eliminate the twist, the diagonal material is straightened without causing twisting. Will be arranged.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to an embodiment shown in the drawings. This is because, as shown in FIG. 1, a triangular mesh, large radius of curvature R _A of the structure longitudinally, an example of application to the curvature radius R _B smaller truss structure of the structure width direction, FIG. 2 FIG. 3 shows the configuration of the space truss structure of the present invention. FIG. 4 shows the details of the joint portion between the truss frame member and the truss node portion of the present invention. FIG. 5 shows the conventional twisting of the diagonal members and the arrangement of the diagonal members at the truss joints according to the present invention. FIG. 6 shows an arrangement state of the truss frame member of the present invention.

In FIG. 1, a truss frame member 1 includes a horizontal member 1A along the longitudinal direction (an arc having a radius of curvature R _A ) of a three-dimensional truss structure, and an oblique (radius of curvature R _B ) with respect to these horizontal members 1A. It is composed of a diagonal member 1B which is disposed (inclined with respect to the arc).

In FIGS. 2 and 3, the truss frame material 1 is C
An upper chord 2 and a lower chord 3 made of a T-section steel and a belly 4 made of an angle steel for connecting the upper and lower chords are formed. Both ends of the truss frame 1 are joined to truss joints 5, respectively. . As will be described in detail later, the truss node portion 5 includes upper and lower joining plates 6 and bundles 7 such as square tubes and round tubes connecting the upper and lower plates.

In the horizontal member 1A, since the central axes of the bundle members 7 of the adjacent truss node portions 5 are located in the same plane and do not twist, as shown in FIG. The attraction point P of the gauge line at the truss node 5 is made to coincide with the center O of the truss node 5.

In the diagonal member 1B, the central axes of the bundles 7 of the adjacent truss nodes 5 are not located in the same plane (see FIG. 5A), and the attractive point Q of the gauge line is changed to the truss node 5 5 is twisted when it is matched with the center O of FIG.
4 (b)), as shown in FIGS. 4 and 5 (b), the attraction point Q of the upper chord member 2 and the lower chord member 3 of the diagonal member 1B by this twist.
_U, shifting the Q _L from the center O of the truss node 5.

As shown in FIGS. 4 and 5 (b), in the diagonal member 1B, the attraction points Q _U and Q of the upper chord member 2 and the lower chord member 3 are obtained.
_L is shifted in different directions by the truss node portion 5 adjacent to attract point Q _L of attracting point Q _U and lower chord member 3 of the top chord member 2 also shifted in different directions, the twist of the diagonal members 1B is eliminated To Shift amount may be set according to the size of the radius of curvature R _B. As described above, by shifting the attraction points of the upper chord member 2 and the lower chord member 3, no twist is generated in the diagonal member 1B as shown in FIG.

As shown in FIGS. 2 and 3, the joining plate 6 of the truss node portion 5 has a structure in which two-stage plates 11 and 12 are connected by a rib 13, and the plate 11 is a truss frame material to be joined. 1 has a protruding portion 11b integrally protruding from the base portion 11a, and has a substantially star shape in plan view. The rib 13 also protrudes from the base 11a to the protrusion 11b.

The projecting portion 11b of the plate 11 is bent with respect to the base 11a by this angle so that the central axis of the bundle 7 and the upper chord 2 and the lower chord 3 make an angle. As shown in FIG. 4, in the case of the horizontal member 1A, the protruding portion 11b is bent at a right angle, but in the case of the diagonal member 1B, the protrusion 11b is bent at an angle.

The projecting portions 11b of the plate 11
The flange and the web of the upper chord 2 or the lower chord 3 are bolted to the rib 13 via the splice plate 14, respectively. The abdominal material 4 is bolted to a gusset plate 15 provided on the bundle material 7 close to the plate 12.

Although the case of the triangular mesh has been described above, it is needless to say that the present invention can be applied to a rhombic mesh and the like. FIG.
An example of a top chord member of the rhombic mesh, also in this case, be shifted to attract point Q _U with respect to the center O of the truss node 5.
Further, in the embodiment, the square pipe is used for the bundle material, but it goes without saying that a round pipe or another shaped steel member can be used.

[0019]

According to the three-dimensional truss structure of the present invention, the attraction points at the truss nodes of the oblique members of the truss frame material which are arranged obliquely are adjusted so that the respective oblique members are not twisted. Are arranged with a slight offset from the center, the following effects can be obtained.

(1) In a three-dimensional truss structure having curved surfaces having different curvatures in two directions, the truss frame member can be joined to the truss node without causing twisting of the truss frame member.

(2) As a result, not only L-shaped steel members (angle irons) but also members having excellent cross-sectional performance such as CT steels, H-shaped steels, and square steel pipes can be used as chord members or web members. Therefore, it is possible to cope with a large-scale structure or a structure having a large load, which was difficult in the past.

(3) The structure of the truss node portion is relatively simple because the protrusion portion from the plate substrate may be formed integrally with the truss frame material so as to protrude integrally and bend. And a compact configuration can be achieved.

[Brief description of the drawings]

FIG. 1 shows an example of a space truss structure having curved surfaces having different curvatures in two directions to which the present invention is applied, (a) is a plan view,
(b) is a front view, and (c) is a side view.

FIG. 2 shows a joint state between a truss frame member (horizontal member) and a truss node part in the present invention, (a) is a top view of an upper chord member,
(b) is a front view, and (c) is a top view of the lower chord material.

3A and 3B show a joint state between a truss frame member (diagonal member) and a truss node part according to the present invention. FIG.
Is a front view, and (c) is a top view of the lower chord material.

4 (a) is a top view of an upper chord material, and FIG. 4 (b) is a top view of a lower chord material, showing a joint portion between a truss frame member and a truss node portion in the present invention.

FIG. 5A is a schematic perspective view showing torsion of a diagonal member in a space truss structure having curved surfaces having different curvatures in two directions,
(b) is a schematic perspective view showing the arrangement of the diagonal members of the present invention.

FIG. 6 (a) is a schematic perspective view showing an arrangement state of a horizontal member and a diagonal member of the present invention, and FIG. 6 (b) is a plan view and a side view of the diagonal member.

FIG. 7 is an example of a case where the meshes of the present invention have different shapes;
It is a top view which shows the joining state of a diagonal material and a truss node part.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Truss frame material 1A ... Horizontal material 1B ... Diagonal material 2 ... Upper chord material 3 ... Lower chord material 4 ... Belt material 5 ... Truss node part 6 ... Joint plate 7 ... Bundle material 11 ... Plate 11a ... Base 11b ... Projection 12 ... Plate 13 ... Rib 14 ... Splice plate 15 ... Gusset plate

Claims (1)

[Claims] 1. A truss frame member having two different directions of curvature by a truss frame member formed by connecting upper and lower chord members via a web member and a truss node to which an end of the truss frame member is joined. In a three-dimensional truss structure that forms a mesh by assembling, the attraction points at the truss nodes of the diagonally arranged oblique members of the truss frame members are adjusted so that twisting does not occur in each of the diagonal members. A three-dimensional truss structure that is slightly offset from the center.