Quasi-static test of assembled steel shear panel dampers with optimized shapes

A metallic shear panel damper with the shape optimized by stress contour lines is proposed in this study to mitigate stress concentration, reduce the effect of hot welds, and improve energy consumption efficiency. The stress contour line is defined according to the J2 plasticity theory, and the optimized shape is obtained by assuming that the points on the same contour line yield simultaneously. Different optimized shapes are developed considering various loading conditions. The design formulas for the stiffness and the strength are then derived, and further examined by nine dampers tested quasi-statically. Four are tested laterally under the vertical axial load to simulate real boundary conditions. All dampers can be easily installed or replaced because of the all-bolt connections. The test results demonstrate that the proposed metallic shear damper has a stable energy-dissipation capacity and a better low-cycle fatigue capability than traditional shear dampers without shape optimization. The stiffness and strength design values match the test values very well. The axial deformation in the specimen has been observed and identified due to the interaction among the cyclic axial-shear coupled plasticity, the geometric nonlinearity, and the higher lateral buckling modes. Compared with the non-optimized damper, the distribution of plastic deformation in the proposed dampers is more uniform, and the stress concentration is reduced significantly.