JPH0113123Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to the provision of a three-dimensional truss frame composed of compression members that are rationally buckled and stiffened.

When considering a space truss, especially a space truss with a large span of 50 to 100 m, buckling of the compressed material is one of the problems.

In other words, the mechanical performance (buckling strength) of the compressed material in a space truss is set by the slenderness ratio evaluated by the length between contact points, but the slenderness ratio is In order to make it a value,
The cross-sectional area of the compressed material must be made large, which leads to an increase in the amount of steel frame and thus to an increase in cost.

This proposal was developed in view of the above-mentioned circumstances, and its gist is that the compressed material in the three-dimensional truss is composed of a small cross-section member with a strong axis and a weak axis, and the bending of the compressed member is After specifying the direction of deflection associated with buckling, stiffeners such as reinforcing bars, which are lighter than the compression member, are placed in the center or at multiple appropriate positions of the compression member in the direction of buckling deformation. By preventing this, we aim to reduce the amount of steel without reducing the mechanical performance of the three-dimensional truss frame.
The point is that it will continue to reduce the cost of large-span space trusses.

This will be explained in detail below based on the drawings.

Fig. 1 is an overhead view showing an example of stiffening the flexible portion of the compression member in the present invention. In the figure, 1 is a compression member such as a top chord member or diagonal member in a three-dimensional truss frame.
In the illustrated example, H steel is used.

Therefore, the compression member 1 has a small cross section and a cross section having a strong axis (in the flange extension direction) and a weak axis (in the direction perpendicular to the web), and the direction of deflection due to bending buckling of the member is in the direction of the weak axis. This is stipulated in the following.

Reference numeral 2 denotes a stiffener which is attached to the center or a plurality of suitable positions of the compressed material in the above-described defined direction of deflection (weak axis direction), and this is compared to the compressed member 1 such as reinforcing bars as shown in the example. One end of the web 1a is fixed to the web 1a via mounting plates 3 and 4 to stiffen the web 1a in the direction of the weak axis.

As shown in the illustrated example, the stiffener 2 may be provided with a jig midway therein to enable adjustment of the length of the turnbuckle 5, etc., to enable introduction of the initial axial force.

As a result, the compression member 1 is rationally stiffened against bending buckling without increasing the amount of steel frame. Figures 2 and 3 show construction examples of three-dimensional truss incorporating compression members stiffened in this way.
and FIGS. 4a and 4b.

Figures 2 and 3 are plan views showing examples of stiffening the upper chord of a space truss when the strong axis is in the out-of-plane direction with respect to the plane of the paper. FIG. 3 shows an example in which a plurality of parts are fastened together. In the figure, 6 is the upper chord member, and 7 is the stiffening point (anchor point).
The other end of the stiffener is fixed at a fixed point 9 to a member 8 that does not undergo buckling deformation in the same plane, such as a member having a strong axis cross section with respect to the plane to be stiffened. The stiffener 2 becomes more rational if it is connected via a plurality of stiffened members (compression members) in the stiffening direction as shown in the figure.

Figures 4a and 4b show diagonal members 10 in a three-dimensional truss.
FIG. 2 is a plan view showing an example of stiffening, and a view taken along the line A-A.

According to the above-described configuration, it is possible to secure a predetermined mechanical performance through slight buckling stiffening without increasing the cross section of the compression member that constitutes the three-dimensional truss frame, so the three-dimensional truss grid can be expanded and It is possible to reduce the number of contacts per unit and reduce the amount of steel.

[Brief explanation of drawings]

Figure 1 is an overhead view showing an example of compression member stiffening according to the present proposal, Figures 2 and 3 are plan views showing an example of three-dimensional truss construction according to the present proposal, and Figures 4 a and b are different types of compression according to the present proposal. FIG. 2 is a plan view and a view taken along the line A-A, showing an example of construction of a three-dimensional truss for stiffening members. 1... Compression member, 2... Stiffener, 7... Stiffening point, 8...
A member that does not undergo buckling deformation, 9... Fixed point.

Claims (1)

[Scope of utility model registration request] The compression member in the three-dimensional truss is composed of a small cross-section member with a strong axis and a weak axis, and the direction of deflection accompanying bending buckling of the compression member is defined, and the center or multiple parts of the compression member are By arranging stiffeners such as reinforcing bars, which are lighter than the compression members, at appropriate locations in the direction of deflection deformation to prevent buckling deformation, the amount of steel can be increased without reducing the mechanical performance of the three-dimensional truss frame. A three-dimensional truss frame characterized by reducing the amount of