Applied Research of Fracture for Brass in Extra-Low Cycle Inverse Rotating Bending Fatigue

摘要

Rotating bending and inverse rotating bending are the two different forms of fatigue. The application of regular blanking for brass under extra-low cycle inverse rotating bending fatigue was investigated. The principle of inverse rotating bending fatigue was explained at first. And then the experiment of inverse rotating bending fatigue was made in special equipment designed by the authors. Several problems, i.e. the relations of the quantities such as cycle times of fracture, the strain amplitude near the notch tip and fracture toughness of fatigue to the presetting deflection, the effects of depth and tip radius of notch on the cycle times of fracture, were discussed with the helps of experiment. Finally, the relation of depth of crack propagation to cycle times were discussed also. The suitable parameters of inverse rotating bending fatigue for blanking of brass were obtained.