Investigation on laminated steel slit shear walls with low yield steel

Abstract

To improve the energy dissipation capacity of steel slit shear walls made of thin plates and mitigate the adverse effects from the large out-of-plane deformation and potential local buckling failure, a novel laminated steel slit (LSS) shear wall assembled from two single-layer steel slit (SSS) shear walls is proposed in this study. First, the theoretical analysis method for predicting the shear strength and stiffness of the LSS shear walls is proposed. To validate the theoretical method as well as investigate the hysteretic performance of the LSS shear walls, two specimens made from different materials, common carbon steel and low yield steel, are designed and tested experimentally under quasi-static cyclic loading. Refined finite element models are developed to simulate the hysteretic behaviors of the LSS shear walls, which show good agreement with the test results. Further, the performance differences between the LSS shear walls and SSS shear walls are analyzed using the validated numerical simulation approach. The strength and stiffness of the LSS shear walls are greater than the summation of the individual SSS shear walls, attributed to the interaction between the different layers in the LSS shear walls. The energy dissipation efficiency of the LSS shear walls is improved and the stiffness degradation is effectively delayed, thanks to the incorporation of the low yield steel material. Finally, to evaluate the effects of the contributing factors on the seismic performance of the LSS shear walls, a series of parametric analyses are performed. Parametric analysis results show that the use of the low yield steel helps to improve the ductility and energy dissipation capacity of the LSS shear walls and delay the stiffness degradation. A large link width ratio, small link length ratio and large link thickness ratio can all contribute to a large strength, stiffness and absolute energy dissipation of the LSS shear walls, but the former two at the same time deteriorate the stiffness degradation.