Strategy for studying thermal oxidation of organic matrix composites

During their thermal ageing in air, organic matrix composite materials undergo superficial oxidation leading to “spontaneous” cracking. In this article, we present the strategy of research built at the laboratory in order to reduce empirism in lifetime prediction. This strategy is based on a model which couples the O2 diffusion and consumption kinetics and gives access to the thickness distribution of all the chemical modifications involved in the ageing process. In this model, all the parameters have a physical sense and can be determined experimentally. Besides, they obey Arrhenius law which is not the case for the usual global rates or lifetimes. After a description of the model and the experiments needed for its optimal use, we present some significant results showing its efficiency. At last, we show how, in a near future, the model will be usable by mechanicians.