Deformation Capacity of Steel Shear Panel Damper and its Reflection to AIJ Design Requirements

Shear panel dampers consisting of stiffeners and panels surrounded by four flanges are used as aseismic hysteretic dampers for buildings in Japan. Cracks can form easily in a shear panel damper when shear buckling occurs during the cyclic loading caused by a severe earthquake. For a relatively thin panel with a large width-to-thickness ratio, the damper’s plastic deformation capacity and the presence of shear buckling can be evaluated from the maximum deformation angle. However, when it is relatively small, very-low-cycle fatigue life for a relatively thick panel must be known to predict the usage limit of the damper, because the failure pattern changes when cracks form in the weld between the panels and flanges. Fatigue life relations for a thick shear panel damper with parameters of normalized width-to-thickness ratio and deformation angle are presented. A method for predicting the fatigue life under severe earthquake conditions is also presented. To validate the prediction expression, cyclic loading tests were performed on a shear panel damper and reviewed. The applicability of the method for predicting the fatigue life was confirmed through non-stationary cyclic loading tests. These results showed the validity and effectiveness of the expressions and the method.