ABSTRACT
In the last years fiber reinforced elastomeric bearings (FREBs) acting as base isolation devices have begun to replace bearings with steel reinforcement. To understand the behavior of FREBs under seismic loads it is essential to investigate their relevant mechanical properties, effective shear modulus and equivalent damping ratio. A parametric Finite Element Analysis was carried out in order to capture the response of circular FREBs under combined compressive and lateral loads. To investigate the influence of the properties of the constitutive materials on the FREB mechanical behavior, a phenomenological based rheological model, accounting for the hyper-viscoelastic behavior of the elastomer and the damage caused by load-unload cycles is set up. A method for the calibration of this material model is presented and validated. The agreement of numerical results with experimental data is assessed. Moreover, the influence of vertical load, horizontal deflection, number of elastomeric and reinforcement layers and support type on the mechanical properties will be discussed.
