Elastomeric bearings manage vertical loads through compression, while their shear resistance governs horizontal movement. Designing these bearings involves achieving an equilibrium between stiffness to withstand compressive forces and flexibility for translational and rotational movement. Typically, the bearing’s cross-sectional area is dictated by the permissible pressure on its support.
However, the plan area can sometimes be limited by the maximum allowable compressive stress to prevent delamination of the elastomer from the steel plates. Additionally, potential separation between the structure and the bearing edge during rotation, which can induce tensile stresses and lead to delamination, is another factor influencing the bearing’s size.
The bearing’s thickness, determined by its horizontal stiffness limitations, is directly linked to movement requirements. It’s crucial to maintain shear strain below a certain threshold to avoid rollover and fatigue damage. To enhance vertical stiffness, a sufficient number of steel plates are incorporated into the bearing’s design.