Fatigue Precracking for Brittle Materials in Compact Tension Specimen by Combined Loading
复合载荷下脆性材料紧凑拉伸试件疲劳裂纹的预制

A new fatigue precracking method for brittle materials was proposed, and it was based on compact tension specimens with combined loading treatment. The method was applied to 7060 T6 aluninum alloy specimens for measuring its fracture toughness. In the method, a frame structure with screw device was employed to impose a compressive load on the two flanks of specimen,and this resulted in the reduction of crack propagation rate in tension fatigue, and therefore controlled the length of fatigue precracking. The experiment showed that with a giving load of tension fatigue and a proper side compression, a demanded crack length can be prefabricated successfully.