铝合金疲劳裂纹扩展声发射监测  

Fatigue crack propagation of aluminum alloy based on acoustic emission monitoring

作　　者：朱荣华[1] 刚铁[1] 

机构地区：[1]哈尔滨工业大学现代焊接生产技术国家重点实验室,哈尔滨150001

出　　处：《焊接学报》2013年第3期29-32,114,共4页Transactions of The China Welding Institution

基　　金：国家自然科学基金资助项目(51175113);国际合作基金(2007DFR70070)资助项目

摘　　要：采用声发射(acoustic emission,AE)技术对7N01铝合金单边缺口三点弯曲试样不同应力比、不同峰值载荷下疲劳裂纹扩展过程中声发射信号进行了监测,建立了裂纹扩展速率、声发射计数(count)与应力强度因子之间的关系.结果表明,大部分的声发射信号主要产生于疲劳循环载荷的低应力阶段,这主要是低应力阶段的声发射活动主要与裂纹尖端的塑性变形和裂纹闭合现象有关,声发射计数与应力强度因子之间呈指数增长的关系.基于所建立的声发射计数率与裂纹扩展速率的关系,可以预测疲劳损伤结构的剩余寿命.The acoustic emission technique was used to monitor the fatigue crack propagation of 7N01 aluminum alloy single-edge notched three-point bend specimens under different stress ratio and peak load.The relationship between the crack growth rate,acoustic emission count rate and stress intensity factor range was established.The results show that most of the acoustic emission signals were produced in the low stress cyclic loading stage because the acoustic emission activity in low-stress phase was mainly related to the plastic deformation and crack closure in crack tip,and the acoustic emission count exponentially grew with the stress intensity factor.Based on the relationship between the acoustic emission count rate and crack growth rate,the remaining life of fatigue-damaged structures could be predicted.

关 键 词：铝合金 声发射 疲劳 计数 

分 类 号：TG146.21[一般工业技术—材料科学与工程]