Chen, Su, and Tang 2011
The purpose of using dampers is to dissipate input energy to the system and avoid inelastic behavior of the primary structural members. This paper explains a new type of damper called the three-pin steel damper. In order to investigate the effectiveness of the developed damper, the nonlinear dynamic responses of designed RC structures with the damper are examined. The experiments show that the energy dissipation mechanism was stable with a large area of hysteresis loops. It can also eliminate the defects of the X type and the triangular type steel damper, called ADAS.
System Concept
Dampers use the stable hysteretic behavior of steel to dissipate input energy. ADAS is a mechanical device made of steel plates with an X or triangular shape and assembled with bolts and/or welds to end blocks. The top of this damper is connected to a girder when the end block is attached to the brace members. In this paper, a new type of damper, a three-pin steel damper, was developed to install on a separate wall within a panel. The three-pin steel damper has hinge-type connections, so that it can be easily produced. Two types of three-pin steel damper were developed. The general difference was the location of intended failure. The Type A damper was designed to ensure that the steel damper remains elastic and the breakage occurs at some distance from the center pin. The Type B damper was designed to let the plastic zone be developed near the center pin, and the breakage extends from the edge of the steel damper to the center pin.
Experimental and Analytical Study, Results, and Discussion
For Type A and B dampers the displacement-control cyclic tests were performed for different displacements; it was seen that the number of cycles leading to failure decreases with increasing displacement.
In the analytical study, a 14-story reinforced concrete building was designed to investigate the effectiveness of three-pin steel dampers. To install the three-pin steel dampers within a panel, a wall-type column was constructed between the top and bottom of beams and cut into two pieces a distance of 500mm apart vertically which was used for the installation. In order to obtain a relation between the story shear and the story displacement, a pushover analysis was conducted.
As a result, the maximum reduction in story ductility ratio is 70% and that in story drift ratio is 54%, so the use of developed dampers was effective in reducing the seismic responses.
Reference
Chen, H.T., Su Y.F., and Tang, H.H. (2011). “The Seismic Responses of 14-Story RC Structures Installed with Three-Pin Steel Damper,” Proceedings of the 8th International Conference on Urban Earthquake Engineering, Tokyo Institute of Technology, Tokyo, Japan, March 7-8.