摘要
超声Lamb波广泛应用于板状材料的无损检测领域。半解析有限元法是求解导波在复杂介质中频散问题的一种计算方法。利用半解析有限元法推导了Lamb波在大型TC4钛合金薄板中传播的理论模型,分析了导波的特点,并选取S0模式对钛合金薄板进行了人工缺陷检测。实验选取S0模式的导波分别对深度为钛合金板厚5%和10%的缺陷进行线性扫描检测,结果显示在有缺陷的地方会出现明显的回波信号。结论表明,Lamb波传播距离远,且覆盖整个金属板,可用于大型板材缺陷的无损检测。
Ultrasonic Lamb wave is widely used in nondestructive testing of the plate material.In this paper,the theoretical model of Lamb wave propagating in the large TC4 titanium alloy sheet was derived using the semi-analytical finite element method to solve the dispersion equation of guided waves in complicated medium,followed by the analysis of the characteristics of guided wave and the test of the artificial defects in titanium alloy sheet using S0 mode.The liner scan was performed using S0 mode guided wave for the defects of titanium alloy sheet which were of 5% thickness and 10%thickness in the experiment.The result showed there was strong echo signal where artificial defects existed.So Lamb wave can be used in nondestructive testing of defects in large titanium plates with the advantages of long propagation distance and large detection range.
出处
《无损检测》
2015年第10期64-68,共5页
Nondestructive Testing
关键词
兰姆波
有限元分析
超声波检测
Lamb wave
Finite element analysis
Ultrasonic testing