A STUDY ON FRACTURE TOUGHNESS AND TEST OF CERAMIC MATRIX COMPOSITES
三维编织CMC的弯曲断裂研究

The works of theoretic studies and numerical simulation are done on the base of interfacial fracture theory in this paper. To TPB, The free constant A in the theoretic expression of energy release rate G is revised by numerical simulation, and the influence of material parameters on energy release rate also is investigated. Hence, a basically integrated theoretic formulation of the fracture toughness is deduced for the TPB test, and is available to tests of single specimen. In one hand, comparing with the test method of marking compliance, this theoretic formulation of the fracture toughness needs lesser specimens of TPB; and in the other hand, the results of tests show that a more steady value of fracture toughness can be obtained by the formulation when rates of specimens notch length a to specimens height W are interval of 0.4 and 0.5.