An approximate model of cylindrical and spherical contact on composite laminates of finite thickness

An empirical force–contact area relationship for the two-dimensional (2D) plane strain line contact between a stiff cylindrical indenter and a composite laminate of finite thickness supported on a rigid substrate is presented. The validity of a 2D Hertzian line contact force–contact length relation originally meant for isotropic contact problems on laminates of finite thickness is first investigated. The same relationship can be applied to orthotropic composite plates provided that an equivalent indentation modulus is known. The indentation modulus can then be corrected for the finite thickness of the plates. The results correlate well with experimental observation. Similar procedures can be performed to find the corresponding correction for a 3D axisymmetric contact problem.