Finite element modeling and validation of recycled rubber-based unbonded fiber-reinforced elastomeric isolators

Seismic isolation is an effective strategy to mitigate earthquake-induced damage. However, the high cost of conventional isolators limits their application in developing countries. This study presents a validated finite element modeling (FEM) framework for Recycled Rubber Fiber-Reinforced Elastomeric Isolators (RR-FREIs), aiming to provide a low-cost and sustainable alternative for seismic protection. The mechanical behavior of recycled rubber was characterized as an incompressible hyperelastic material using the Ogden model, while fiber layers were modeled as transversely isotropic. Experimental data from tension, compression, and shear tests were used to calibrate and validate the numerical models developed in ABAQUS, incorporating viscoelasticity and the Mullins effect. In parallel, a Bouc-Wen model was implemented in OpenSees to reproduce the hysteretic behavior for structural applications. The FE model predictions showed strong agreement with experimental results, with energy dissipation and stiffness errors below 10% in most cycles. The validated models confirm that RR-FREIs provide adequate damping and horizontal flexibility for low-rise buildings, demonstrating their feasibility as sustainable, cost-efficient seismic isolators. This work establishes a practical modeling framework for the design and optimization of recycled elastomeric isolators in resource-limited regions.