薄壁LY12铝合金焊接残余应力超声波法无损测量及验证

Residual stress evaluation of thin-plate LY12 by ultrasonic method and verification

摘要: 传统残余应力破坏测量方法无法满足焊接结构服役状态下的应力测量,无法实现结构的无损应力测量.基于声弹性原理,超声波法可以无损测量出结构内部的残余应力.使用临界折射纵波进行薄壁结构件测量时,易激发Lamb波和Stonely波等特殊波形,将影响测量的准确度.开发了适用于薄壁结构件测量的新型超声波法焊接残余应力测量系统,对厚度为2mm的两种LY12薄壁焊接结构进行了测量,测量过程实时无损快速.用切割释放法和有限元模拟进行了验证.结果表明,该测量系统准确可靠,为航天器薄壁焊接结构服役状态在线可靠性评估奠定了基础.

Abstract: Residual stresses are one of the most important challenges to the safety of welded structures.Ultrasonic stress measurement installation was modified to meet the measurement of thin wall welded structure.The residual stress of LY12 body structure of high-speed train was measured by this system.The measurement process is not only nondestructive, but also real-time and quick.The measuring result of the ultrasonic method is verified by laser hologram interference hole-drilling method and finite element method.The deviations are also discussed.