Mechanical behaviour and lifetime modelling of self-healing ceramic-matrix composites subjected to thermomechanical loading in air

The simulation of the behaviour and lifetime of composites with self-healing ceramic matrix requires the coupling of models issued from both mechanics and chemistry. The mechanical macromodel is based on a partitioning of damage according to the various degradation mechanisms. Analysis windows on the microscale enable the reconstruction of the crack network indicators and of the opening states of the cracks as functions of the loading. The self-healing mechanism is modelled by creating an oxide plug in an open crack and simulating the diffusion of oxygen through its evolving geometry. An evolution law for fibre strength as a function of oxygen concentration provides an illustration of the influence of complex thermomechanical loading on the composite’s lifetime.