Comparison of horizontal response of square and circular – unbonded fiber reinforced elastomeric isolators with same cross-sectional area by finite element analysis

Abstract

ABSTRACT:
Unbonded fiber reinforced elastomeric isolator (U-FREI) is a new seismic elastomeric isolator which has been studied and developed in the world. Horizontal response of an U-FREI is affected by both shear modulus of rubber as well as contact area of the isolator with the supports due to rollover deformation. In this paper, horizontal response of square and circular U-FREIs with the same cross-sectional area subjected to vertical load and cyclic horizontal displacement simultaneously is investigated by finite element analysis. Comparison the mechanical properties of these isolators shows that effective horizontal stiffness of circular U-FREI is higher than that of square UFREI at large applied displacement.

Keywords: Base isolator, unbonded fiber reinforced elastomeric isolator, effective horizontal stiffness, cyclic horizontal displacement