Frictionless contact of layered metal-matrix and polymer-matrix composite half planes

Abstract

This paper examines the differences and similarities in the response of metal-matrix and polymer-matrix composite half planes indented by a rigid, parabolic punch. The quantities of interest are the load versus contact length and the normal stress distribution in the contact region. In particular, the effect of material properties and off-axis ply orientation on these quantities is investigated for homogeneous and layered configurations. Layered configurations include [0°/±45°] layer sequences bonded to 90° half planes, as well as to a half plane with significantly lower elastic stiffness moduli. The analysis is conducted using a recently developed solution method for frictionless contact problems of arbitrarily layered half planes consisting of isotropic, orthotropic, or monoclinic layers. The results indicate that homogeneous metal-matrix composite half planes exhibit a substantially stiffer load versus contact length response than homogeneous polymeric matrix half planes owing to their higher transverse material parameters, in particular the transverse Young's modulus, E 33. In situations where local bending is present, which occurs in sandwich-type configurations with a substantially softer substrate, the ratio of the longitudinal to transverse Young's moduli plays a significant role for the considered laminate configurations. In this case, the normalized contact stress profiles of certain metal-matrix and polymer-matrix composites exhibit substantial departures from elliptical that appear similar in shape despite differences in the actual magnitudes of the material parameters.