SMOOTH CONTACT OF ORTHOTROPIC LAMINATES BY RIGID CYLINDERS

An analytical method is developed to investigate the contact behavior of an orthotropic laminate indented by a frictionless cylinder. The me thod is derived from an exact Green's function, which is based on the anisotropic elasticity theory in the plane strain condition. The conta ct response of a laminate is characterized into small and large contac t stages depending on conformation of the curvatures between the inden ter and the laminate in the contact region. The large contact stage oc curs after conformation of the curvatures, resulting in less stress co ncentration in the laminate. It is found that the large contact stage readily develops when large indenters or large laminate span-to-thickn ess ratios are used. Also, the effect of slight misalignment of an ind enter on the contact response of the laminate is significant. On the o ther hand, a change of laminate stacking sequence has an insignificant effect on the force-indentation relationship.