Finite deformation of compressible bonded rubber mounts

Bearings for bridges, earthquake isolation bearings for buildings, and elements in vehicle suspensions may be made from one or more layers of elastomer between rigid steel plates to which the elastomer is bonded. Using simplifying assumptions based on previous work, simple and explicit forms of solution are developed for finite (non-linear) deformation of bonded blocks, in plane or axisymmetric strain, with special reference to compressible elastic materials. The qualitative behaviour of the explicit form of solution is reasonable and on linearizing it agrees with published experimental and theoretical results for small deformation. The explicit form of solution also compares well with such experimental results as are available for finite deformation and with finite element calculations. Application of the results to laminated blocks, where compressibility is expected to be important is illustrated, and an assessment of the effect of the bulk compressibility of the rubber is offered.