JPH0723655B2 - Air film structure - Google Patents

Description

TECHNICAL FIELD The present invention relates to an air film structure, and specifically to a cable arrangement for suppressing deformation of the film material.

《Prior art》 In a roof with a membrane structure, if the membrane that forms the ceiling is greatly deformed by being blown by the wind, etc., the internal lighting equipment will be destroyed. The cables are arranged vertically or horizontally or diagonally, and the cables are connected in the arrangement as shown in FIG. 4, for example.

The cable 1 shown in the figure is arranged on the diagonal line of the square ring beam 2 and in parallel with this at a constant interval.

<< Problems to be Solved by the Invention >> The air film structure with the cable arrangement as described in the conventional example has the following problems as shown by referring to FIG.

That is, in the air film structure, pressurized air slightly higher than the atmospheric pressure above the ground is filled into the structure, and the film material is bulged upward by the pressure to obtain a function as a ceiling portion of the structure.

In this case, the cable 1 is also lifted by the bulging of the film material, but at the same time, the cable 1 also bears the wind pressure on the film material.

Therefore, since the cable 1 bears pressure on the beam 2, its tensile stress becomes a bending moment that bends the beam 2 inward, and the beam 2 is constantly bent as shown by beam 2a in the figure. It was necessary to enlarge the shape.

The present invention has been made in view of the above circumstances, and an object thereof is to provide an air film structure that can be configured by a ring beam having a small cross-sectional shape.

<< Means for Solving the Problem >> In order to achieve the above-mentioned object, the air film structure of the present invention is configured by tightly connecting all corners of a ring beam formed in a polygonal shape and substantially the inner center point of the ring beam. A ridge cable is arranged, and a ring cable is attached and fixed between the ridge cables so as to be substantially similar to the ring beam so as to surround the inner center point of the ring beam. The feature is that the deformation is suppressed.

<< Operation >> The deformation stress of the membrane material is received by the ridge cable and the ring cable, and the force received by the ring cable is borne by the ridge cable. Since the stress of the ridge cable acts on all corners of the ring beam in a balanced manner as tension that pulls the stop line of the interior corner or the vicinity thereof toward the inner center point of the ring beam, it acts on each adjacent side of each corner. The acting moments cancel each other out, and a compressive force acts on each side of the ring beam to maintain the mechanical structure of the self-balancing system.

<Example> Hereinafter, a preferred example of the present invention will be described in detail with reference to the drawings.

In the following invention, the same reference numerals are used for the same or corresponding portions as the above-mentioned conventional example.

FIG. 1 is a plan view showing a cable arrangement for suppressing the deformation of the membrane material. In the ring beam 2 assembled in a quadrangle near the top of the outer wall of the structure, it is stretched on the diagonal line connecting the opposite corners. The installed cable 3, that is, the ridge cable 3 is stretched. Next, a ring cable 4 is provided between adjacent ridge cables 3-3 in parallel with the beam 2, and a ring cable 4 is circulated between the ridge cables 3-3 in a similar shape to the beam 2. In the figure, the ring cables 4 are provided in triples from the small ring cables 4 to the large ring cables 4a and 4b with the intersection of the ridge cables 3-3 as the center.

The intersection of each ridge cable 3 and the ring cable 4 is tightly connected.

Note that the ring cables 4 do not necessarily have to be provided separately for each similar shape, and may be provided in a spiral shape as indicated by a chain double-dashed line in the figure.

Therefore, as shown by the arrow in FIG. 2, the deforming force of the film material (not shown, but double-attached to each cable 3 and 4 so as to be locked to each cable) is transmitted through the ridge cable. Transmitted to the beam 2. This transmitted force becomes a force that pulls the center line of each corner of the ring beam 2 toward the inner center of the ring beam 2, and is converted into an axial force that compresses each side of the ring beam 2. Therefore, it does not act as a bending moment on the ring beam 2.

FIG. 3 (A) shows the case where the ring beam 2 is hexagonal, FIG. 3 (B).
Shows the arrangement of the ridge cable 3 and the ring cable 4 in the case of an octagon, and FIG. 8C shows the arrangement of the ring cable 4 and the ring beam 2 each having a similar shape to the ring beam 2. Ridge cable 3 tied from the center to the inner center point
And the same operation as that of the above-described embodiment of FIG.

The cable arrangement in which the ridge cable 3 is coupled to the inner center point and the ring cable 4 surrounding the ridge cable 3 is similar to the ring beam 2 is the most ideal in the present invention, but the tight connection point of the ridge cable 3 is slightly different from the inner center point. The case where the ring cable 4 is placed in an eccentric position, or the ring cable 4 becomes somewhat dissimilar to the ring beam 2 is unavoidable.

<Effect> As described in detail above, according to the air film structure of the present invention,
The deformation stress of the film material is received by the ridge cable and the ring cable, and the force received by the ring cable is borne by the ridge cable. However, the stress of the ridge cable is at the inner corners of all corners of the ring beam. Since the central line or its vicinity acts in a balanced manner as a tension that pulls toward the inner center of the ring beam, the moments acting on the adjacent sides of each corner cancel each other out, and A compressive force acts and thus maintains the mechanical structure of the self-balancing system. In addition, since the ring cable is installed between each ridge cable so as to surround the inner center point of the ring beam in a shape similar to that of the ring beam, the deformation stress of the film material is finely transmitted to the ridge cable, resulting in a mechanically very balanced balance. A compressive force can be applied to each side of the ring beam in a smooth shape.

Therefore, the cross-sectional area of the ring beam can be made significantly smaller than that of the conventional example. This is also advantageous in terms of construction. Especially, in terms of the vertical load and bending moment that the strut of the ring beam bears, the ring beam is not likely to be deformed by the bending moment and the ring beam is reduced in weight. The burden on the beam columns can be reduced.

[Brief description of drawings]

FIG. 1 is a plan view showing an embodiment of the present invention, FIG. 2 is an explanatory view showing mechanical properties of FIG. 1, and FIGS. 3 (A) (B) (C).
Are plan views showing other embodiments, FIG. 4 is a plan view showing a conventional example, and FIG. 5 is an explanatory view showing mechanical properties of FIG. 1 ... Cable, 2 ... Ring beam 3 ... Ridge cable, 4 ... Ring cable

Claims (1)

[Claims] 1. A ridge cable is arranged by tightly connecting all corners of a polygonal ring beam to substantially the inner center point of the ring beam, and the ridge is arranged so as to surround the inner center point of the ring beam. An air film structure characterized in that a ring cable is attached and fixed between the cables in a shape similar to that of a ring beam, and the deformation of the film material is suppressed by the ridge cable and the ring cable.