Document Type : Original Article

Author

• Mohammad Moein Akbari

Master's degree, Department of Civil Engineering, Faculty of Engineering and Technology, Razi University, Kermanshah, Iran.

Abstract

This study aims to investigate the influence of internal reinforcement type—steel plates versus fiber layers—on the stress–strain demand and force–deformation response of elastomeric bearings under lateral and vertical loading. The novelty of the work lies in the comparative approach: both bearing types are designed with identical geometric dimensions and similar elastomeric material properties, allowing the reinforcement layer to be isolated as the sole varying parameter. The behavior of steel-reinforced elastomeric bearings (SREB) and fiber-reinforced elastomeric bearings (FREB) is examined using finite element analysis. For both bearing types, unbonded support conditions are considered. In this configuration, the bearings are placed between the superstructure and substructure without mechanical attachment, and shear forces are transferred to the supports through friction at the contact surfaces. The numerical models are used to assess the resulting stress distribution, strain demand, and global deformation response in both the vertical and lateral directions. The findings indicate that in unbonded applications, FREB bearings experience significantly lower internal stress demand compared with SREB bearings. This reduction is particularly pronounced for tensile stresses acting normal to the interface between the reinforcement layers and the elastomeric material. In addition, the effective lateral stiffness of FREB bearings is noticeably smaller than that of SREB bearings. The results demonstrate that the type of internal reinforcement has a substantial impact on the mechanical behavior of elastomeric bearings under combined vertical and lateral loading. Fiber reinforcement leads to a meaningful reduction in both internal tensile stresses and lateral stiffness in unbonded configurations. These outcomes highlight the potential advantages of fiber-reinforced bearings for applications where reduced stress demand and greater flexibility are desirable.

Keywords

• Seismic isolator
• Elastomeric bearing
• Fiber reinforcing layers
• Finite element analysis
• Unbonded application

Main Subjects

• structure