Seismic response of floor-anchored nonstructural components fastened with yielding elements

Failure of nonstructural components during an earthquake can lead to structure functionality loss, cause widespread property damage, and pose a life-safety threat to the occupants. Current code provisions for floor-anchored components aim to minimize the life safety threat by specifying lateral force demands and anchoring requirements. These code requirements are based on a simplified equation that does not fully consider the contribution of the attachment to the overall component dynamic response. Previous results from shaking-table tests of anchored components suggest that the component attachment is an important parameter that determines its dynamic properties. For this study, a nonstructural experimental model was attached via several attachment designs to a concrete slab and tested on a shaking table to evaluate this contribution. The attachments were dimensioned based on a capacity design approach, such that they would be the weakest element in the force path while providing a yielding mechanism. The attachment designs provide different plastic mechanisms that control the displacement ductility in the response of the component. This paper focuses on the contribution of the attachment to the dynamic response and seismic force demand on the component. The experimental results demonstrate that the selected attachment properties govern the boundary conditions of the nonstructural component and strongly influence its dynamic response. The more flexible attachments sustained large deformations, leading to tensile membrane action and enhanced tensile strength in the attachments. Consequently, the ductile attachments did not result in reduced seismic loads in the nonstructural components.