超声双折射法测试铝合金的内部应力  

Measurement of stress in aluminum alloy by acoustic birefringence

作　　者：魏勤[1] 董师润[1] 徐秉汉[2] 徐颖梅[1] 

机构地区：[1]江苏科技大学数理学院,镇江212003 [2]中国船舶科学研究中心,无锡214082

出　　处：《应用声学》2008年第5期401-406,共6页Journal of Applied Acoustics

基　　金：江苏省船舶先进设计制造技术重点实验室开放课题资助(163220129)

摘　　要：声各向同性的金属材料在应力作用下表现出声各向异性,这是用声弹性法分析材料内部应力的基础。本文用偏振方向平行或垂直于应力方向的超声纯横波对LY11型铝合金进行测试。实验结果表明:材料在拉、压单轴应力作用下,偏振方向平行和垂直于应力方向的超声纯横波的声速都发生了变化。实验在分析材料声各向异性的基础上计算材料声弹性双折射系数,得到测试LY11型铝合金内部应力的理论公式,并对其内部的残余应力进行评估。实验中利用双换能器回振法测量声速,时间测试精确度可达10^(-11)s,可精确测量声速的微小变化量。Acoustic anisotropy effect occurs when a isotropic metal is submitted to stress which is the base of measurement of stress in material by acoustoelastic effect. In this paper, orthogonally polarized pure mode shear waves were used to test LY11 Aluminum alloy. Experimental results show that the presence of stress causes small changes in phase velocities of shear waves, which is called acoustoelastic birefringence effect. The acoustoelastic coefficients are acquired by the analysis of the acoustic anisotropy, and theoretical equations of measuring stress in material are obtained. Furthermore, the residual stress is evaluated. The phase velocities are measured by a sing-around method by which small changes in velocity can be detected. The precision of time interval can reach to 10^-11 s.

关 键 词：声双折射 回振法 应力测试 残余应力 

分 类 号：TU431[建筑科学—岩土工程] V241.4[建筑科学—土工工程]