Section: Application Domains

Self healing composite materials

In a collaboration with the UMR LCTS we are studying the influence of the in-crack physico-chemistry on the lifetimes of self healing composite materials. The self healing character of these materials is given by the presence of a reactive phase in the composite matrix which reacts with oxygen and yields a liquid oxide with a very high specific volume (compared to the reactive). The extra volume occupied by the oxide gives a protecting layer shielding the composite fibers from farther oxidation. The failure mechanism of these materials is thus strongly dependent on the evolution of this oxide.

Our objective is to develop a simplified asymptotic model of the physics and chemistry of a single crack, to be used as a numerical closure model for structural mechanics computations. This model as to provide time integrated values of oxygen concentrations at fibers, which can be used to infer fiber weakening and rupture, thus to change the crack topology. This process can be iterated until failure is obtained. Our contribution consists in developing the chemistry and flow models, related discretization, and implementation in an ad-hoc module which will be coupled with the structural solver of LCTS.