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

Seismic Behavior of Thin Cold-Formed Steel Plate Shear Walls with Different Perforation Patterns

Thin perforated Steel Plate Shear Walls (SPSWs) are among the most common types of seismic energy dissipation systems to protect the main boundary components of SPSWs from fatal fractures in the high risk zones. In this paper, the cyclic behavior of the different circular hole patterns under cyclic loading is reported. Based on the experimental results, it can be concluded that a change in the perforation pattern of the circular holes leads to a change in the locations of the fracture tendency over the web plate, especially at the plate frame interactions. Accordingly, the cyclic responses of the tested specimens were simulated by finite element method using the ABAQUS package. Likewise, perforated shear panels with a new perforation pattern obtained by implementing Topology Optimization (TO) were proposed. It was found that the ultimate shear strength of the specimen with the proposed TO perforation pattern was higher than that of the other specimens. In addition, theoretical equations using the Plate Frame Interaction (PFI) method were used to predict the shear strength and initial stiffness of the considered specimens. The theoretical results showed that the proposed reduced coefficients relationships cannot accurately predict the shear strength and initial stiffness of the considered perforated shear panels. Therefore, the reduced coefficients should be adopted in the theoretical equations based on the obtained experimental and numerical results. Finally, with the results of this study, the shear strength and initial stiffness of these types of perforated shear panels can be predicted by PFI method

Experimental and Numerical Study of Perforated Steel Plate Shear Panels

Thin perforated Steel Plate Shear (SPS) Walls are among the most common types of energy dissipating systems. The applied holes reduce the shear strength of the plate and allow to decrease the profile size of the members at the boundary of the panel when these systems are used in the typical design of structures. On the other hand, the different fracture locations of these panels are visible when considering the different perforation patterns. This paper reports on the results obtained from the experimental study under cyclic loading of the effect of different hole patterns on the seismic response of the systems and the location of the fracture. According to this, two perforated specimens by different patterns were considered. In addition, a plate without holes for a better comparison of the fracture location was chosen. The results showed that changing the pattern of the holes causes a change in the fracture location. Moreover, in perforated specimens, the amount of shear strength did not reduce suddenly after the fracture phenomenon. In the specimen which was perforated around the web plate, the pinching force was more than any other in the low cycle of the drifts. For this reason, the energy dissipation and initial stiffness were more than up to 3% drift. The experimental specimens were then simulated with a Finite Element (FE) method using the ABAQUS. Finally, a parametric FE analysis on different series of perforated panels, by changing the diameter of the holes and the plate thickness, has been carried out