Damage Coupled With Heat Conduction in Uniaxially Reinforced Composites

This paper presents a continuum damage model for a unidirectionally reinforced composite based upon fundamental concepts of continuum mechanics and irreversible thermodynamics. Damage is incorporated by two symmetric, second-rank, tensor-valued, internal state variables which represent the total areas of “active” and “passive” cracks contained within a representative material volume element. Constitutive relations are derived for both the mechanical response and heat flux in the presence of damage. It is shown that damage growth contributes to dissipation in the coupled heat conduction process. A specific fracture mechanics solution is employed to relate “microlevel” crack growth processes to “macrolevel” damage growth expressions. This approach lends itself to a probabilistic formulation of the continuum damage model.