应用声发射技术评价材料疲劳损伤的研究

Research on Evaluation of Material Fatigue Damage by Acoustic Emission Technology

从疲劳损伤会导致材料力学性能和微观结构发生变化，并由此产生产发射这一事实出发，根据累积振铃计数在疲劳试验过程中的变化情况，定义了材料损伤的两个阶段。在此基础上，提出了一个描述材料累积损伤的模型。结果表明，此模型的预测结果与试验结果吻合较好。结合微观分析，从理论上对材料损伤各个阶段的机理作了进一步的探讨。

Based on the fact that material fatigue damage will cause change of its mechanical behaviors and microscopic structure accompanied by acoustic emission (AE), two phases of material damage are defined according to the changes of accumulative counts of acoustic emission during the fatigue test. On this basis, a mathematical model describing the variation of material damage is established. It is shown that this model gives results that agree quite well with test results. Through microscopic observation, the mechanism underlying material damage in the two phases is further approached theoretically.