JP4552129B2 - Tense grid structure - Google Patents

Description

  The present invention relates to a tense grid structure suitable for application to, for example, a roof frame in a large-scale facility.

  The tense grid structure is a kind of stringed truss structure as shown in Patent Document 1, and a large number of grid units A (also called tensegrity) as shown in FIG. The frame of the form is configured.

That is, as shown in FIG. 3, the grid unit A as a constituent element in the tense grid structure is composed of four grid members 1 made of steel pipes, steel bars, etc. in a frame shape (square shape in the illustrated example) to form a frame body 2. Then, a bundle member 3 made of a steel pipe, a steel rod, or the like is also arranged inside the frame body 2 so as to intersect a surface (a plane in the illustrated example) formed by the frame body 2 , and both ends of the bundle member 3 and the frame A total of eight diagonal members 4 each made of a cable are stretched with a predetermined tension between each apex of the body 2.

  Then, as shown in FIG. 4, a single-layer grid frame B is formed by combining a large number of grid units A and connecting the vertices of the frame bodies 2 to each other, and a bundle 3 of adjacent grid units A. By connecting the upper end portions and the lower end portions of each of them with a chord member 5 made of a cable to which a predetermined tension is applied, the entire single-layer grid frame B is supported by the chord member 5 to form a stable tense grid structure. Is. Such a tense grid structure is sufficiently lightweight and capable of a large span, and is a self-balanced and naturally stable frame. For example, the roof frame of a large-scale facility such as a stadium or a gymnasium It is suitable for application to.

By the way, the above tense grid structure is basically a single-layer and lightweight frame, so it is inevitable to deform and vibrate somewhat when subjected to an external force such as seismic force or wind force. As the span becomes longer, deformation and vibration are more likely to occur. Therefore, in order to ensure the desired deformation performance and seismic performance, the grid frame B is made sufficiently high by increasing the cross section of each member or using a high-strength material. The design is usually stiffened, thereby ensuring load bearing capacity and deformation capacity. In addition, it is also considered to incorporate a seismic isolation device, a damper device or the like into this type of frame to control and attenuate the vibration. For example, in Patent Document 2, a damper (such as a TMD unit) is added to the bundle 3 in the grid unit A described above. It has been proposed to incorporate a tuned mass damper.
JP 2000-54492 A Japanese Patent Laid-Open No. 11-2048

  However, in this type of tense grid structure, it is not always easy to increase the rigidity of the entire frame only by designing the cross-section and strength of the members. It is not preferable because it is damaged and disadvantageous in terms of cost. In addition, it is not practical to use a special device such as a TMD damper because a significant increase in cost is inevitable.

  In view of the above circumstances, an object of the present invention is to provide an effective tense grid structure capable of improving vibration characteristics and seismic performance at a low cost without sacrificing the original lightness.

According to the first aspect of the present invention, a bundle member is arranged inside a frame body formed by assembling grid members in a frame shape so as to intersect a surface formed by the frame body , and both ends of the bundle member and the frame body A grid unit in which a diagonal member made of a cable is stretched between each vertex of the grid unit is used as a constituent element, and the vertexes of the frame body of the grid unit are connected to each other to form a single-layer grid frame and adjacent to each other. A tense grid structure in which the grid unit bundle members are connected by a string member made of a cable and tension is applied to the string member, and instead of a cable as a string member at a key point of the grid frame, using a damping member in which the grid frame to absorb the external force as plastic strain energy by plasticized when deformed by an external force, such as seismic forces and wind, the said damping member And characterized by being arranged so as not to intersect the plane formed by the lid frame.

  The invention of claim 2 is the tense grid structure of the invention of claim 1, characterized in that a steel rod having a small cross section is used as the damping member.

  The invention of claim 3 is the tense grid structure of the invention of claim 1 or 2, wherein the grid frame has an arch shape, and a damping member is provided on a pin support portion of the grid frame or a hinge portion formed by an external force. It is characterized by becoming.

  According to the present invention, the damping member can be made to function as a vibration damping damper only by replacing a part of the cable as a string member in the conventional general tense grid structure with the damping member. Deformation performance and seismic performance can be improved naturally.

  In addition, a steel bar with a small cross section can be suitably used as the damping member, and if it is used, the cost increase is negligible, and the tense grid structure with excellent seismic performance is most economically realized. Is possible.

  Furthermore, by applying the present invention to an arch frame and providing a damping member at the pin support portion or hinge portion, the damping effect on the entire arch frame can be obtained most efficiently.

  One embodiment of the tense grid structure of the present invention is shown in FIGS. This shows an example in which the conventional tense grid structure shown in FIG. 4 is applied to a three-hinge arch.

In the tense grid structure of the present embodiment, the grid unit A shown in FIG. 3 is used as a component, and a large number of them are connected as shown in FIG. Although the grid units A are basically connected to each other by a string member 5 made of a cable, a three-hinge arch frame is constructed in which both ends and the top are substantially pin-supported as shown in FIG. As shown in FIG. 1, as the chord member 5 provided at the top, a damping member 6 having damping performance is used instead of a cable, and the damping member 6 is a surface formed by the grid frame B (in the illustrated example, an arch). In other words , the damping member 6 employs a simple steel bar having a small cross section.

  The steel rod as the damping member 6 has a tensile strength that allows the grid units A to be connected to each other in the same manner as the cable as the other chord material 5 at normal times. When the member 6 is deformed or vibrated by an external force such as force or wind force, the damping member 6 is designed to be plasticized by the external force. In this case, the external force is generated by the plastic strain energy generated by plasticizing the damping member 6. Is effectively absorbed and the seismic control effect on the grid frame B is exhibited. That is, as shown in FIG. 2, the steel rod as the damping member 6 exhibits a restoring force characteristic similar to that of a normal steel damper, and can exhibit a sufficient energy absorption effect during an earthquake or a strong wind. .

  Therefore, according to the tense grid structure of the present embodiment, the damping member can be obtained simply by replacing a part of the cable as the chord member 5 in the conventional general tense grid structure with the damping member 6 made of a steel bar having a small cross section. 6 can effectively function as a vibration damper (steel damper), and the deformation performance and seismic performance of the entire frame can be naturally improved. Of course, the steel rod as the damping member 6 is an inexpensive construction material, and it is not difficult to install it as a string material 5 instead of a cable. Therefore, the cost increase required for this is negligible. The weight is not impaired as in the case of increasing the rigidity of the grid frame B by increasing the cross section and strength of the member as in the conventional case, and it is significant as in the case of incorporating a special damping device such as TMD. It is possible to economically construct a tense grid structure with excellent seismic performance without increasing costs.

  In addition, since the tense grid structure of the said embodiment is an application example to a 3 hinge arch frame, the installation position of the damping member 6 is set to the top part used as a hinge part, and thereby the damping effect with respect to the whole frame is obtained most efficiently. However, the installation position of the damping member 6 may be set to an optimal position so that a desired damping effect can be obtained according to the form and scale of the entire frame, and distributed installations at multiple locations as necessary. You can do it. Of course, the form of the frame by the tense grid structure of the present invention is not limited to the three-hinge arch, but can be widely applied to frames of various forms, scales, and uses.

  Further, in the above embodiment, a steel bar having a small cross section is used as the damping member 6. However, the damping member 6 is assumed to have a predetermined tensile strength required as the chord material 5 in a normal state. Any material capable of exhibiting desired damping performance during an earthquake or strong wind may be used, and as long as it is not limited to a steel rod, it does not preclude the adoption of other materials and members.

It is an elevation view which shows the tense grid structure which is embodiment of this invention. It is a figure which shows the restoring force characteristic of a damping member. It is a figure which shows the grid unit which is a component of a tense grid structure. It is a figure which shows the basic composition of a tense grid structure.

Explanation of symbols

A Grid unit B Grid frame 1 Grid material 2 Frame body 3 Bundle material 4 Diagonal material (cable)
5 String material (cable)
6 Damping member (steel bar)

Claims (3)

A bundle member is arranged inside a frame body made of a grid material in a frame shape so as to intersect a surface formed by the frame body, and between the both ends of the bundle member and each vertex of the frame body A grid unit formed by stretching diagonal members made of cables is a component,
The vertices of the frame body of the grid unit are connected to each other to form a single-layer grid frame, and bundles of adjacent grid units are connected to each other by a string material made of cable to apply tension to the string material. Tense grid structure
Instead of a cable as a chord material at the main point of the grid frame, a damping member that plasticizes when the grid frame is deformed by receiving external force such as seismic force or wind force and absorbs the external force as plastic strain energy is used. The tense grid structure is characterized in that the damping member is arranged so as not to intersect the surface formed by the grid frame .   The tense grid structure according to claim 1, wherein a steel bar having a small cross section is used as the damping member.   3. The tense grid structure according to claim 1, wherein the grid frame has an arch shape, and a damping member is provided on a pin support portion of the grid frame or a hinge portion formed by an external force. Construction.

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