H. Shakib - Department of Civil Engineering, Tarbiat Modares University, Tehran, Iran
M. Ahmaddieh - Department of Civil Engineering, Yazd University, Yazd, Iran

This study has been performed to evaluate the effects of different input motions on the response of pure-friction base isolated asymmetric buildings subjected to simultaneous three components of earthquake excitations. The pure-friction base isolated asymmetric building is idealized as a three-dimensional single-storey building resting on sliding supports. The plan wise distributions of structural stiffness are asymmetric relative to the xand y-axes. Thus, the center of rigidity (CR) of the structure is eccentric relative to CM (i.e.ex and ey). However, the center of mass (CM) of the top mass and the base mass are assumed to be vertically aligned. The sliding surface is modeled by interface rigid contact elements. The frictional stresses mobilized at the sliding support have ideal coulombfriction characteristics, which is implemented in the analysis by assuming elasto-plastic behavior with very high initial stiffness. The response of the system subjected to threecomponent (including vertical component) and two-component (excluding vertical component) of earthquake excitations is investigated for different earthquakes with different characteristics. The performance of asymmetric pure-friction base-isolated system is investigated with the help of peak response ratio of sliding to fixed base systems. It is observed that the earthquake characteristics significantly affect the response of purefriction base isolated asymmetric buildings.

Earthquake characteristics, pure-friction, asymmetric building, threecomponent of earthquake