Abstract
Many industrial structures are built under complex loads. Some irregular loads cause cracks or defects in the structure. Then fatigue causes crack growth from these cracks under mixed mode. The condition of these crack tips turn to mode I domination by crack growth. Because general fatigue crack growth is progressed under mode I domination, mode I fatigue crack growth rule had been derived by many researches. However, a fatigue crack growth rule under mixed mode has not been established. Measurement of crack growth from irregular initial crack is difficult.
In this study, crack growth experiments are operated to obtain basic data for fatigue crack growth under mixed mode. Slanted cracks are installed in three point bending specimens. Crack growth tests are demonstrated for some slant angle. Mixed mode condition is caused at the front of the slant crack. Crack growth rate, fracture path and others are discussed as these experimental results.
