Simplified prediction of stresses in transversely isotropic composite plates under Hertzian contact load

This paper proposes an efficient approximation for the local stresses in transversely isotropic plates under Hertzian contact loads. The approach uses superposition of available closed form solutions for contact stresses in a half space and the stress field according to classical plate theory. A parametric study ranging from a highly three-dimensional case to a flexure dominated case is performed by varying the contact radius from one tenth to twice the plate thickness. Comparisons with a three-dimensional finite element analysis demonstrate that the suggested approach yields small errors for the entire range of cases studied. Finally it is shown that contact stresses in a transversely isotropic material may result in a peak of the maximum shear stress on the loaded surface which contrasts to the results for isotropic materials. Improved prediction of experimentally observed damage is noted when comparing with previously adopted isotropic contact stress analyses.