پیمان نرج آبادی فام

Modern structural engineering is approached with an innovative Isolation System (IS) devised for aseismic control of structures. The proposed IS has been made up of hosting steel-PTFE Flat Sliding Bearings (FSBs) accompanied by auxiliary simply connected superelastic Shape Memory Alloy (SMA) truss elements. It is referred to as Smart Restorable Sliding Base Isolation System (SRSBIS). The FSBs support gravity loads while allowing isolation displacements and the SMAs provide necessary restoring capability with a proper horizontal stiffness. SMA elements in SRSBIS can alternatively be arranged for vertical, bracing, and horizontal configurations. Depending on the arrangement of the SMA elements, SRSBIS can exhibit a geometric nonlinearity in addition to the nonlinearity of materials. The system is first characterized for its structure, mechanical behavior, dynamic properties, and seismic performances. A mathematical model is particularly developed for SRSBIS and the design procedure is sketched following a direct displacement based method. Comprehensive parametric analyses, then, clarify the effects of the changes in system variables. Application details are further investigated in the case study, referred to a four-story building equipped with rubber isolators. Force-displacement relationships, shear forces, inter-story drifts, and story accelerations are studied. Comparison is made between SRSBIS and other practical ISs. Shake table test are finally conducted on a reduced-scale test- structure. Based on the results, the applicability of SRSBIS incorporating SMAs together with FSBs is verified. It is shown that this kind of aseismic design can effectively control the structural responses.