Abstract

Laser ultrasonic nondestructive testing technology can effectively detect the location of cracks and other information, it is easy to realize the qualitative detection of cracks, but it is difficult to achieve quantitative detection of cracks. In this paper, based on the traditional nonlinear ultrasonic method, ultrasound excited by laser. Combining the characteristics of laser ultrasonic waveform, the nonlinear ultrasonic coefficient of laser and the nonlinear ultrasonic model of laser are deduced. Through the establishment of experimental samples, the transmission and reflection of two ways to experiment were conducted, the experimental data are processed by nonlinear coefficients of laser ultrasonic, obtaining the relationship between coefficient and the depth of the crack, and the results are compared with the simulation data, The results show that the laser nonlinear ultrasonic model can support the nonlinear ultrasonic coefficients of the laser, and the laser nonlinear ultrasonic can represent the depth of the crack to a certain extent and realize the quantitative detection of the crack.

中文翻译：

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基于非线性超声系数的激光超声无损检测

摘要

激光超声无损检测技术可以有效地检测出裂纹的位置及其他信息，很容易实现裂纹的定性检测，但是很难实现裂纹的定量检测。本文基于传统的非线性超声方法，通过激光激发超声。结合激光超声波形的特点，推导了激光的非线性超声系数和激光的非线性超声模型。通过建立实验样品，进行了两种方式的透射和反射，利用激光超声的非线性系数对实验数据进行处理，得到了系数与裂纹深度的关系，并与结果进行了比较。模拟数据