Correcting for the influence of bulk compressibility on the design properties of elastomeric bearings
Journal of Engineering Mechanics
The compression and bending modulus of elastomeric bearings, commonly applied as vibration isolators, are important design considerations. Analytical solutions have demonstrated that the sensitivity to the compressibility of the elastomer can be significant and begins at relatively low shape factors. These analytical solutions, which include the effects of compressibility on the compression and bending modulus, are often complex and not suitable for design purposes. Alternatively, an ad hoc approximation has been recommended that expresses the compression and bending modulus, including the compressibility of the elastomer, by assuming incompressibility and correcting with the bulk modulus. It is demonstrated that the ad hoc approximation provides an unconservatively large value of the compression and bending modulus for infinite strip, square, circular, and annular pad geometries. A correction factor to the ad hoc approximation is determined by expanding and simplifying the analytical solutions. The proposed approximations typically reduce the magnitude of the error while also providing a conservatively lower estimate of the compression and bending modulus.
Van Engelen, Niel C. and Kelly, James M.. (2015). Correcting for the influence of bulk compressibility on the design properties of elastomeric bearings. Journal of Engineering Mechanics, 141 (6).