Stress Intensity Factors of Interface Crack under Arbitrary Material Combinations (Effects of Relative Crack Length)
Naoaki NODA, Yu ZHANG, Kentaro TAKAISHI and Xin LAN
Abstract:Although a lot of interface crack problems were previously treated, few solutions are available under arbitrary material combinations. This paper deals with periodic interface cracks in a bonded infinite plate and a central interface in a bonded infinite plate. Then, the effects of material combination and relative crack length on the stress intensity factors are discussed. A useful method to calculate the stress intensity factor of interface crack is presented with focusing on the stress at the crack tip calculated by the finite element method. For periodic interface cracks, it is found that the stress intensity factors are controlled by the bimaterial parameter alone and increase with increasing and relative crack length. For a central interface crack, the relationship between the dimensionless stress intensity factors FT ,FU and relative crack length a/W are obtained under arbitrary material combinations. It is found that FT has the maximum value when =0.2 ,=0.3 and minimum value when =1.0 , =0 independent of@a/W . On the other hand, FU has the maximum value when =0.1 , =0 and minimum value when =0.2 ,=0.3. Key Words:Elasticity, Interface strength, Stress intensity factor, Fracture mechanics, Finite element method