兰姆波各模式声速与板材疲劳关系研究

Study on relationship between the Lamb wave velocity and the fatigue of plate

摘要: 为了研究由于材料疲劳造成的材料弹性系数变化对兰姆波各模式相速度的影响,对兰姆波传播特性进行了理论计算与实验测量。研究表明高阶模式兰姆波相速度对于弹性系数的变化要比零阶模式敏感。对于LY-12-CZ合金铝板,A₃模式由于材料疲劳产生的相速度相对变化量要比A₀模式约高4倍。因此采用高阶模式兰姆波进行无损检测,其灵敏度要远优于当前常用的零阶模式。

Abstract: In order to study the influences on the phase velocities of different modes of the Lamb wave due to the variations of elastic coefficients caused by the material fatigue,the propagation characteristics of the Lamb wave are studied by simulations and experiments.It is found that the velocity shift of the high mode Lamb wave is more sensitive to the variations of elastic coefficients than that of the low mode.In a LY-12-CZ aluminum plate,the velocity shift of the A₃ mode is about 9 times larger than that of the A₀ mode.Then,high sensitivity can be obtained by using the high modes of the Lamb wave in the nondestructive examinations.