Hysteretic behavior of steel shear panels with internal rectangular-shaped links

A novel typology of steel shear panel based on a web plate perforated according to Rectangular-Shaped Links (RSL) with internal links is proposed, to act as an energy dissipation element and improving the progressive overstrain behavior of typical shear plates. Preliminary experimental tests were carried out to investigate the behavior of the proposed system and to determine the influence of the main design parameters on the hysteretic response of tested specimens. The obtained outcomes evidenced that the shear strength, the stiffness and energy dissipation capacity of proposed shear panels are consistently influenced by overstrain in bending around the rectangular-shaped links, due to the slenderness of internal links. In particular, two different buckling modes were identified, namely global shear buckling of the plate, which is partially dissipative, and lateral-torsion buckling of individual rectangular-shaped links and internal links, which may result fully dissipative. Then, a FEM model has been implemented and validated according to the experimental results. Therefore, a parametric analysis has been carried out, considering the main parameters affecting the cyclic response of the specimen. The obtained outcomes allowed to conclude that the polar moment of inertia of links could be used together with the plate thickness to control the hysteretic performance of RSL specimens. In particular, the increasing of the width of internal links could allow the activation of global buckling of the plate, which generally causes significant pinching of hysteretic cycles. Based on the conducted parametric analyses, optimum web plate slenderness ratio and polar moment of inertia of links have been identified, providing useful suggestions for design of the proposed shear panel typology. In addition, an equation to predict the yielding shear strength of these kinds of shear panels has been suggested.