THERMOELASTIC MODEL FOR MULTIDIRECTIONAL COATED-FIBER COMPOSITES - TRACTION FORMULATION

In this work a companion model to that given earlier is developed to approximate the thermoelastic response of a composite body reinforced by coated fibers oriented in various directions. The fundamental representative volume element is a three-phase concentric circular cylinder under prescribed surface tractions which are independent of the axial coordinate. The analysis leads to a lower bound calculation of the effective moduli which, together with the upper bound results, provides a more precise estimate of the overall composite properties. A parametric study has been further conducted to illustrate the effect of different coating materials and thicknesses on the effective properties and micro-stress distribution within the constituents of a three-dimensional fibrous composite subjected to a uniform temperature change. © 1990.