抄録
In a previous paper, the authors proposed a method of simulating the behavior of a fatigue crack propagating in bonded dissimilar materials by using an equivalent specimen made of single constituent material, and proved in successful with bonded copper-steel (Young's Modulus Ratio : 1.7) plates. This paper is concerned with experimental simulation studies of fatigue crack propagation paths near or across the bonded interface with bonded titanium-copper (YMR : 1.2) and titanium-steel (YMR : 2.0) plates, by using this proposed equivalent specimens. Single-edge-cracked equivalent plate specimens with a 15° or 45° slant interface were used, which was simulated by thickness discontinuity. When a crack propagated from the low to the high Young's modulus side, the crack grew along the interface except for the case of titanium-copper with 45° slant interface. When the initial crack was in the high Young's modulus side, the crack propagated almost straight across the interface, if the interface had enough strength, These behavior agreed quite well with those obtained by BEM numerical simulations of fatigue crack propagation based on the Δσ_θ maximum criterion, which were conducted in a separate paper.
