Numerical modeling of seismic behavior of ellipse and peanut-shaped auxetic steel plate shear walls

Abstract

This study proposes a new auxetic-shaped steel plate shear walls (simply referred to as ASSPSWs) consisting of boundary members and built-in perforated infill plates. The connection type between the boundary members is a hinge joint. The hole forms on the infill plates include orthogonal ellipse-shaped (ASSPSW-OE) and orthogonal peanut-shaped (ASSPSW-OP). This paper studied the hysteretic performance of two steel plate shear walls’ types based on the finite element analysis method. Within the study context, a parametric analysis was carried out to investigate the influence of various factors, such as hole size and hole distance, on the seismic performance of steel plate shear walls (SPSWs). The results indicated that reducing the the ratio of the ligament thickness to ellipse major axis (t/D) in orthogonal ellipse-shaped SPSWs can effectively increase the porosity while reducing the bearing and energy dissipation capacities. Under the condition with the t/D unchanged, increasing the ratio of the major to minor axis of the ellipse (d/D) raises the porosity and does not significantly reduce the bearing capacity and energy dissipation capacity of the SPSWs. For orthogonal peanut-shaped SPSWs, the holes’ geometrical parameters significantly influence the hysteretic performance. Particularly, with the increase in the radial ratio of large to small circles in a peanut-shaped hole (R/r), the spacing between cells decreases. When drift exceeds 2%, the equivalent viscous damping ratio decreases sharply. Unlike the orthogonal ellipse-shaped SPSWs, changing the arrangement angle of peanut-shaped cells has no significant effect on orthogonal peanut-shaped SPSWs. However, the larger the angle, the greater the out-of-plane buckling of orthogonal ellipse-shaped SPSWs; thus, the energy dissipation capacity is reduced. The similarities lie in that the larger cell arrangement angle will make the steel plates have a complete stress field, and the bearing capacity will be slightly improved. When the cell arrangement angle (θ) is 45°, the SPSWs can develop high initial stiffness.