SEISMIC PERFORMANCE OF STRUCTURES WITH LATERAL LOAD RESISTING SYSTEMS OF VISCO-ELASTICALLY CONNECTED FLEXURAL SHEAR

To enhance the seismic performance of the conventional flexural-shear type structures, e.g., frame-shear wall system, a visco-elastically connected flexural-shear structural system is proposed. In this system, the flexural- and shear-type lateral load resisting systems (LLRS) are connected by visco-elastic elements (VEE), and corbels are set on the shear wall to support the VEEs, while the VEEs are rigidly connected to the floor deck on the frame. Deforming spaces are set between the floor slab and the shear wall to accommodate the relative displacements between the flexural- and shear-type LLRSs. Some experimental tests are conducted to reveal that the dynamic shearing behavior of the VEE is not influenced by the vertical pressure acting on the top. Using the validated shearing model (for VEE) as well as the combined flexural and shear spring model (for the primary structure), the dynamic analysis model for the visco-elastically connected flexural-shear structural system is established. A parametrical seismic response analysis is conducted. The analysis results show that an approximate 30%-reduction in the seismic force demand of the shear wall could be achieved due to the limited inertial forces transferred from the frame to the shear wall. Thanks to the additional damping introduced by the visco-elastic element, both the global displacement and the floor acceleration are well controlled (reduced by 15% ~ 40%). Demonstrating such good features, the peak deformation of the visco-elastic element is less than twice of the inter-story drift of the primary structure.