MICROMECHANICAL MODEL FOR THERMAL ANALYSIS OF PARTICULATE AND FIBROUS COMPOSITES

Abstract

Thermal stresses occur at the micromechanical level of a particle-/fiber-reinforced composite caused by the mismatch of coefficients of thermal expansion (CTE) of the constituent materials like the particle/fiber and the matrix binder. The stresses affect the service envelope of a composite structure when it is subject to an external load. Thus, this ankle presented a simplified, analytical, three-dimensional, micromechanical model so as to compute microthermal stresses occurring in the constituent materials as well as the effective CTE of a composite based on their materials properties. The analytical solutions for both particulate and fibrous composites were compared to the results obtained from finite element analyses as well as other results if available. The comparison of the effective CTEs and the microthermal stresses between the present solutions and the finite element results showed an excellent agreement. In addition, a parametric study was conducted in order to determine the effects of each parameter of the constituent materials on the effective CTE, microthermal stresses, and the solution errors. The orthogonal array technique used in the Taguchi method was adopted for the parametric study.