抄録
A method of strength evaluation based on fracture mechanics is important to analyze the fracture strength of material with crack. The heterogeneity of mechanical property in dissimilar materials causes change of fracture behavior. Analysis of mechanical property and fracture strength in dissimilar materials is important to evaluate fracture toughness with accuracy. The purpose of this paper is experimentally to analyze correlation between Young's modulus ratio and fracture toughness in dissimilar materials with a single edge crack. 4 kinds of specimen were used in this experiment. One was homogeneous material, the others were 3 kinds of dissimilar materials. The fracture behavior of dissimilar materials was analyzed by high-speed video camera and digital image correlation method. Then, specimens were bended and displacement near the crack was measured. Fracture toughness was experimentally calculated based on fracture mechanics. The experimental results showed that fracture energy and strain distribution around a crack tip were same values at all specimens. We conclude that relationship between Young's modulus ratio and fracture toughness in dissimilar materials is uncorrelated. Then, the heterogeneity of Young's modulus causes the change of crack opening displacement.
