Introduction of the convex friction system (CFS) for seismic isolation

This work introduces an innovative seismic isolation system named the convex friction system (CFS). This newly introduced isolation system has a sliding concavity with a circular cone-type surface, and exhibits some distinct features compared to conventional isolation techniques, such as increased uplift stability, improved self-centring capacity, and resonance dodge when subjected to near-fault earthquakes. A series of comprehensive analytical and numerical investigations are performed to verify these features of the CFS. First, the force-displacement relation of the CFS is established to describe the underlying philosophy of the system. The analytical model is then incorporated into numerical simulations to evaluate the seismic isolation performance of the CFS. Various ground accelerations, such as near-fault shakings, are included in these numerical calculations. Furthermore, the numerical results are rigorously investigated to illustrate the feasibility of the CFS. Finally, the limitations of the CFS study are discussed, and conclusions are drawn. The analytical and numerical results show that the CFS performs well in seismic isolation applications. The structural response can be reduced by approximately 30% with the CFS when compared to that with the Curved Surface Slider (CSS) with a spherical-surface concavity for some near-fault earthquakes, which verifies the aforementioned advantages of the CFS. Copyright (C) 2016 John Wiley & Sons, Ltd.