In this study, the influence of shapes of hysteresis dampers using bent steel plates for base-isolated structures (BSPD) on the deformation capacity is investigated. In chapter1, conditions which improve deformation capacity is suggested with reference to the Ref.13). In chapte2, the influence of steel plate shapes on the mechanical behavior (e.g., yield strength, initial stiffness, and equivalent plastic strain) is investigated by FE analysis. In chapter3, the cyclic shear loading tests are conducted to investigate the deformation capacity of BSPDs. The experimental parameters are steel plate shapes selected in Chapter2. The conclusion of these chapters are as follows.
1. The yield strength and initial stiffness increase as α increases, or h decreases.
2. When α = 0, the yield strength differs between 0° and 45° loading direction. When α = 0.4 or more, the loading
direction has little influence on the yield strength.
3. Failure modes are classified according to the load amplitude and direction. In the case of 0° loading direction, the crack propagates along the circular plates when d = 100mm, and the crack propagates from diagonal plates when d = 200mm. On the other hand, in the case of 45° loading direction, the crack propagates perpendicularly to the loading direction from the circular plates, regardless of the loading amplitude.
4. The deformation capacity increases as α decreases, or h increases.
5. Compared to the previous BSPD13), the deformation capacity is largely improved by 1) eliminating of the bolt holes on end plates, and 2) using LY225.
6. There is a correlation between the magnitude of equivalent plastic strain obtained by FE analysis and the deformation capacity of BSPD.
