Steady-state creep of fiber-reinforced composites: constitutive equations and computational issues

Abstract

The general form of the constitutive equations that describe steady-state creep of fiber-reinforced metal-matrix composites with transversely isotropic overall symmetry is developed. The physical meaning of the constitutive functions involved is discussed in detail. A method for the numerical integration of the constitutive equations is developed. The “linearization moduli” associated with the integration algorithm are computed, and the constitutive model is implemented in a general purpose finite element program. A constitutive model for steady-state creep of fiber-reinforced composite that has been developed recently by deBotton and Ponte Castañeda (1993) is also considered. A number of “unit cell” problems with periodic boundary conditions, consistent with the requirements of homogenization theory, are solved by using the finite element method, and the results are compared with the predictions of the analytical model of deBotton and Ponte Castañeda.