Cyclic behaviour of low-yield-point steel shear panel dampers

In this paper, a new type of low-yield-point steel BLY160 is applied in the metallic shear panel damper device. To intensively investigate the seismic behaviour of the dampers, reversed cyclic loading tests are conducted to four groups of specimens, with the loading conditions and dimension parameters as test variables. The influences of the width-thickness ratio and corner perforation of the panel, the stiffening rib size and the cyclic load history are analysed. Through the experimental performance of test subassemblies, such as the hysteretic load-displacement loops, skeleton curves, deformation behaviour and failure modes, the earthquake mitigation effects of the damper devices are evaluated. In particular, conspicuous work-hardening is observed in the condition of cyclic deformation under both constant amplitude and increasing amplitudes loading. Contributed by the cyclic hardening of the low-yield-point steel, the energy dissipation capacities of the tested damper devices are approximately 1.5-2.5 times higher than that of a steel panel made of equivalent elasticity and perfectly plastic material. The complicated hysteretic performance with significant strain hardening can be accurately simulated by the kinematic-isotropic combined hardening model proposed in this paper, which incorporates the loading history effect by using the memory surface concept. The validity of the numerical model is verified by the comparison of the predicted cyclic behaviour and test responses.