激光超声检测表面裂纹深度的数值模拟

发布时间：2017-12-27 10:28

本文关键词：激光超声检测表面裂纹深度的数值模拟　出处：《激光技术》2017年02期 　论文类型：期刊论文

【摘要】：为了研究激光冲击所引起的瑞利表面波在材料表面裂纹检测方面的作用,采用ABAQUS建立了激光超声无损检测表面裂纹的模型,并模拟激光在材料表面激发瑞利波及瑞利波沿材料表面传播的过程。从激光的峰值压力、空间分布、时间分布3个方面将激光冲击作用等效成力的作用,体现了激光参量在作用过程中所起到的作用;同时,使用无限单元消除了边界的反射回波。通过对接收点处瑞利表面波信号的分析,进行了不同深度表面裂纹对瑞利波回波峰值影响的定量比较。结果表明,瑞利反射波的正向峰值与下一次最大正向位移所对应的时间的比值和表面裂纹深度之间存在着线性关系,进而为实验测量表面裂纹深度提供了一种测量方法。
[Abstract]:In order to study the effect of Rayleigh surface wave induced by laser shock in the detection of material surface crack, established by ABAQUS laser ultrasonic nondestructive testing of surface crack model, and simulate the process of material in laser excited surface Rayleigh and Rayleigh wave propagating along the surface of the material. From the 3 aspects of laser peak pressure, spatial distribution and time distribution, the effect of laser shock is equivalent to force. It reflects the role of laser parameters in the process of action. At the same time, the infinite element is used to eliminate the reflected echo of the boundary. Through the analysis of the Rayleigh surface wave signal at the receiving point, the quantitative comparison of the influence of the surface crack of different depth on the peak value of the Rayleigh wave echo is carried out. The results show that there is a linear relationship between the ratio of the peak time of Rayleigh reflection wave to the time of the next maximum positive displacement and the depth of the surface crack, which provides a measurement method for measuring the depth of the surface crack.
【作者单位】：中国矿业大学力学与建筑工程学院;中国矿业大学深部岩土力学与地下工程国家重点实验室;
【分类号】：O426;;TN247
【正文快照】： 州221116)引言表面裂纹大量地存在于工程构件当中,如何快速准确地识别它们已成为无损检测的任务。普通的检测方法不适用于高温、高压、有毒[1]等恶劣环境,而激光超声无损检测凭借其非破坏、非接触[2-3]等优点克服了这种局限性,并且具有较高的精度,成为了无损检测的一个重要研

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