Numerical investigation on ultimate shear strength of steel plate shear walls

• Interaction of plate and boundary elements influenced ultimate shear strength of SPSW.
• Base shear supported by boundary elements was proportional to tensile strength of plate.
• Use of flexible boundary elements reduced base shear supported by plate.
• Current codes inertia requirement for columns does not account for number of floors.
• Columns of SPSWs should be designed to limit in-ward deflections in bottom panel.

Ultimate shear strength of steel plate shear walls, SPSW, was conventionally computed as the sum of base shear supported by in-fill plate and boundary frame elements. The base shear supported by the in-fill plate was computed assuming that it was fully yielded after buckling whereas the base shear supported by the boundary frame elements was computed by plastic analysis assuming uniform yielding mechanism. In this paper the ultimate shear strength of SPSW was investigated by the finite element method. A detailed three-dimensional finite element model was established using ANSYS software at which the in-fill plate and the boundary frame elements were modeled using finite strain iso-parametric shell elements. The analysis included material and geometric non-linearities. Numerical results obtained from cyclic and pushover loading of SPSWs were verified by comparison to test results published in the literature. A comprehensive parametric analysis was conducted to assess the effect of geometric and material parameters of the wall on its ultimate shear strength. Discrepancies between numerical results and conventional theory were attributed to interaction of in-fill plate and boundary frame elements at ultimate load. When the flexural rigidity of boundary frame elements decreased, the in-fill plate did not achieve full yield strength. On the other hand, the base shear supported by boundary frame elements increased when thicker in-fill plates were utilized. Numerical results were used to update the theoretical expression of ultimate shear strength of SPSWs. The proposed expression was assessed by comparison to test results published in the literature.