An Empirical Model for the Design of Rubber Shear Bushings

Abstract

Abstract The objective here was to formulate guidelines for the design of a particular class of rubber bushings exhibiting nonlinear load/deflection behavior. This was accomplished by the derivation of an empirical model of bushing performance based on data from a designed experiment. The data from a two-level, full factorial experiment with six design variables were reduced to equations for the prediction of ten response variables. The range of applicability of the prediction equations was extended with an effective dimensional analysis, validating similarity relationships of the system's variables. Thus, an empirical model useful for the first approximation of rubber shear bushing design is established. Further details regarding this model are contained in Reference 3. The nonlinear load/deflection characteristics of rubber shear bushings offer a designer several unique features to utilize advantageously. The plateau region near the center of their stroke provide bushings with low stiffness in their operating range. Unlike linear springs, nonlinear bushings can achieve their load carrying requirement for the operating range while maintaining compact package size. Although similar to Belleville washers in that geometric parameters can be varied to tailor the load/deflection behavior, rubber bushings offer an additional design variable by virtue of their material. The stiffness and damping properties of rubber compounds are readily modified to attain a desired bushing performance.