声发射技术对材料疲劳过程的损伤特征的研究(英文)

Study of Damage Characteristics during Fatigue by Acoustic Emission Techniques

文章考虑损伤效应,研究材料疲劳过程损伤特征及相对应的声发射活动性。导出的疲劳损伤演化方程具有与声发射活动相似的Paris公式形式,发展了研究裂纹声发射活动的损伤力学方法。又通过分析损伤对塑性区尺寸的影响,提出塑性区损伤修正模型。采用该修正模型的预测结果与实验结果基本吻合。并以声发射参数为损伤变量提出声发射活动中的损伤发展规律。经试验数据分析,文中提出的塑性区修正模型可以较好地反映声发射活动规律,损伤发展规律符合试验观察结果。

Damage characteristics during fatigue and acoustic emission （AE） activities accounts for damage effect on material are studied.Damage evolution equation similar to the well-known Paris＇ formula is derived, as well as AE activities. A damage mechanics approach is applied to investigate AE activities. According to the damage effect on the size of plastic zone, a modified model for the plastic zone with damage is presented,which shows that the results of this proposed model are in a good agreement with experiments. Considered AE parameter as damage variable, the rule of damage evolution during AE activities is developed.Predictions by the proposed model are more consistent with the test data. And the damage evolution law is coincident with the experimental results.