兰姆波各模式成像研究

Study on the Images of Different Order Mode Lamb Waves

为了研究兰姆波各模式的成像质量,对兰姆波传播特性进行了理论计算与仿真成像实验。研究表明,高阶模式兰姆波的相速度对于弹性系数的变化要比零阶模式敏感,且高阶模式成像拟合的圆半径与实际半径均方差较小,即成像质量优于零阶模式。因此,采用高阶模式进行成像分析,其成像质量优于当前常用的零阶模式。

In order to study the imaging quality of different order mode Lamb waves, the propagation of the Lamb wave are studied by theoretical calculation and simulation experiment. It was found that the velocity shift of the high order mode Lamb wave was more sensitive to the variations of elastic coefficients than that of the low mode, and the radius of the Lamb wave was closer to the actual radius, the image quality was better than low modes. Thus high image quality could be obtained by using high modes of Lamb wave in the analysis of image.