Finite element study on vertical characteristic of modified circular perforated-reinforced elastomeric isolators (MC-PREIs)

This research presents the vertical characteristics of Modified Circular Perforated-Reinforced Elastomeric Isolators (MC-PREIs) under compression. Research on base isolation was undertaken to derive the lowest horizontal stiffness to obtain the fundamental period of an isolated structure, typically for light structures, such as residential housing. To achieve this purpose, geometric modifications were introduced by reducing the loaded area of the isolators. Prior to observing the horizontal characteristic, the vertical stiffness of MC-PREIs was considered to ensure that the interior modification influences the vertical characteristic of the isolator. Therefore, understanding of vertical characteristics due to interior modification was required. In this study, experimental vertical test results of Perforated-Reinforced Elastomeric Isolators (PREIs) were used to verify three-dimensional (3D) finite element (FE) model analyses of ANSYS. Furthermore, the 3D finite element models were used to undertake a parametric study on three MC-PREI configurations with different geometries. The FE method investigation considered the influence of the geometric modifications on the vertical stiffness and the compression modulus, in addition to strain and stress distribution in the perforated reinforcement and elastomer. The finite element analysis indicated that the greater reduction area in the isolator generated decreases significantly in compression modulus and vertical stiffness in addition to increasing the stress distribution on both rubber and perforated plate under compression.