Elastomeric bearing sizing analysis Part 2: Flat and cylindrical bearings

This analysis covers rigorous development of theoretical equations based on linear elasticity and the assumption of rigid shims (i.e. reinforcements) used in the following bearing sizing computer programs for general three-dimensional loading: Flat (circular) Single Pad, Flat Multilayer, Partial Cylinder (single and multilayer), Complete Cylinder (single and multilayer). Essentially the same methodology based on perturbation theory is used for spherical, flat and cylindrical bearings, and thus the theory was very detailed for only the spherical bearing in Part 1. Part 1 includes equations for predicting beam-column action and buckling for quite general bearing geometries, loads and deformation modes, including tensile, shear and bending. For the two geometries in Part 2 the analysis is less detailed, and differences in the theory, if any, are noted. All equations have been programmed using Mathcad embedded in Excel for ease of use by the designer. The beam-column analysis requires at least two pads, thus necessitating a separate single-pad program. Sample results are shown in this paper for stiffness as a function of shape factor, including comparison with finite element predictions, and for selected displacement, stress, and strain distributions.