Modelling of the mechanical behavior of a 2.5D C C composite under tensile and shear loads at room temperature

A macroscopic model of the non-linear stress-strain behavior and the ultimate failure of a 2.5D Carbon/Carbon composite is proposed. It is based upon continuum damage mechanics concepts and it was guided by extensive microscope observations of the damage mechanisms under load at room temperature. The model involves three scalar damage parameters including a shear parameter resulting from a combination of the tensile ones. Only three uniaxial tensile tests are required for parameters identification. Then, a fair agreement was obtained between the calculated and the measured stress-strain curves for various loading conditions. The ultimate failure was predicted using damage accumulation criteria.