Finite element analysis of matrix crack deflection mechanisms in f iber-reinforced composites

The axisymmet ric finite element models of the mat rix crack deflection/ penet ration for two -phase andthree-phase composites were established respectively by applying the energy-based crack deflection criterion. Theeffects of the fiber volume f raction , the Dundurs parameter αdescribing the elastic mismatch between material properties , and the relative crack growth length a_d / a_p on the relative energy release rate ratio G_d / G_p were investigated.The FEA result s were compared with those obtained by He for two-phase composites , and the effect s of the interphase thickness , Dundurs parametersα₁ andα₂ on G_d / G_p were further studied for three-phase composites. The SiCfiber-reinforced composite SiC/ C/ Ti-6Al-4V and ceramic composite SiC/ C/ SiC coated with cabon were analyzed bythe FEA respectively , and the result s show that the models can accurately predict and compare the mat rix crackdeflection mechanisms.