损伤力学给予我们评估材料的损伤程度及预测剩余寿命以有力的理论依据和手段。但是 ,评估材料损伤程度的损伤参量的确定却是比较困难的。人们对疲劳过程中材料的微观组织结构变化已进行了大量的表象的研究 ,但是这些变化与材料损伤程度之间的关系却是不很明确的 ,特别是由驻留滑移带转化为微观裂纹这一阶段。作者采用不同程度的低周疲劳后再进行冲击试验的方法 ,可以从冲击试验的载荷 挠度曲线及扫描电镜断口照片上清晰地看到随着低周疲劳损伤程度的增加 ,沿晶断裂及二次裂纹的百分数增加 ,并且由此导致了撕裂功的增加。所以 ,对于低周疲劳损伤程度的评估 ,可以用冲击韧性试验再配合以扫描电镜断口分析的方法来获得。 Damage mechanics gives us a powerful theoretical basis and means to evaluate the degree of material damage and predict the remaining life. However, it is difficult to determine the damage parameters to assess the degree of material damage. There are a lot of studies on the microstructural changes of materials in the process of fatigue, but the relationship between these changes and the degree of material damage is not very clear, especially from the resident slip zone into micro-cracks This stage. The authors use different degrees of low cycle fatigue and then the impact test method, you can from the impact test load deflection curve and the scanning electron microscope fracture picture clearly shows that with the low cycle fatigue damage increased, intergranular fracture and secondary The percentage of cracks increases, and as a result an increase in tearing work. Therefore, for the assessment of the degree of low cycle fatigue damage, you can use impact toughness test combined with scanning electron microscopy fracture analysis to obtain.