Investigation on crack problems of functionally graded materials under thermal shock

An analyzing model was proposed by combining the interaction energy integral method with the finite difference method and the finite element method to investigate the thermal shock cracks of the functionally graded materials(FGMs). The transient thermal stress intensity factors(TSIFs) of the FGMs were obtained. The effect of the normalized crack length on the transient TSIFs was investigated. The crack propagation under thermal shock was discussed. The results show that, (1) the peak value of the transient TSIF is the major factor to affect the fracture failure of the FGMs at the early stage of the thermal shock; (2) the crack length has a significant influence on the peak value of the TSIF; (3) the FGMs with the higher fracture toughness have a better thermal shock resistance.