Modeling damage growth in oxidized high-temperature polymeric composites

Thermal oxidation is a major degradation mechanism for polymers and composites operating at high temperatures. Controlling the damage progression in oxidative environments is critical for enhancing the long-term durability of these materials. The surface oxidation of the material and the damage evolution in high-temperature polymer matrix composite materials (HTPMCs) are highly coupled mechanisms. In this article, three-dimensional, finite-element methods are used to simulate both oxidation layer and damage growth in polymers subjected to bending loads and laminated composites subjected to uniaxial tension. An oxygen diffusion-reaction model determines the changes in properties due to oxidation and chemical strains induced by oxidation. The damage growth is simulated using mesh-free extended finite-element techniques and suitable damage initiation laws. The damage evolution observed with simulations is seen to be consistent with experimental observations reported in the literature.