Hysteretic Behavior of Rubber Bearing with Yielding Shear Devices

Using the perforated yielding shear plates as an energy dissipated device instead of lead core in rubber bearing is assessed in this paper. The advantage of this innovative isolator compared to lead rubber bearing is the ability of being replaced easily and its less displacement with high ability of energy dissipation. Three different isolators with perforated shear plates with hole cross-section of 15%, 18%, and 33% of cross-sectional of plate surface area are investigated. Three types of shear plates of 2, 3 and 4 mm thicknesses made of two types of steel with different yield stress are assessed. By decreasing the shear plate thickness and increasing the number of the plate holes and selecting the shear plate with lower yield stress, the effective stiffness and the amount of energy dissipation and lateral force in the isolator are reduced. Changing shear plate thickness and number of holes do not affect the viscous damping, while increasing the plate yield stress increases viscous damping. Therefore the choice of the shear plate with appropriate thickness, number of holes and plate yield stress can lead to an isolator with acceptable behavior. The suggested isolator can achieve similar characteristics of lead rubber bearing at 50% shear strain and therefore its design basics should be defined differently rather than lead rubber bearing.