Finite Element Modeling of a Fiber-Reinforced Elastomeric Isolator Made With a NR-BIIR Blend

Elastomeric isolators are special devices for the seismic isolation of structures. They are typically made of alternating layers of steel or fiber-reinforced laminas and rubber pads. They are interposed between the ground and the foundation to increase the structure's natural period and reduce the damaging effect on the structure due to the earthquakes. This study proposes a detailed 3D FE modeling of fiber-reinforced elastomeric isolator (FREI), carried out through the FE software code Abaqus. The isolator understudy is constituted by several alternating layers of rubber pad made of a natural rubber-bromobutyl blend (NR-BIIR) and four GFRP laminas. In addition, it presents unbonded conditions to reduce production costs and allow its applicability in developing countries. So, the upper and lower edges do not exhibit any bond with the supports. The main feature of such a device is the large deformability thanks to the rollover deformation and the favorably lower lateral stiffness compared to the bonded isolator.