基于声表面波的V型裂纹快速检测数值研究

Numerical Study on Rapid Detection of V-Shaped Cracks Based on Surface Acoustic Wave

为了实现对金属表面V型裂纹深度的快速检测,本文研究了声表面波与一定深度范围内的V型裂纹的作用过程,采用有限元方法模拟了热弹机制下,线性脉冲激光源激发的声表面波信号在金属材料中的传输过程,以及声表面波与V型裂纹的相互作用。研究结果表明,不同深度的V型裂纹和声表面波有不同的相互作用。通过分析不同深度裂纹与声表面波的作用机制,将裂纹深度信息划分为三个范围区间,并推算出了相应的裂纹深度的计算方法。本文根据作用过程的不同,提出了一种对金属表面V型裂纹深度进行快速判断和检测的方法。该方法通过检测声表面波反射回波信号RR和转换横波信号RS峰值的大小,可对V型裂纹的深度范围进行快速判断,然后检测出其深度信息。该方法可以快速定位裂纹深度区间,提高了金属表面V型裂纹深度信息的检测效率。模拟结果表明,裂纹深度计算值和实际值之间的误差均不超过5%,该方法可以实现对金属表面V型裂纹的高效检测。

This study seeks to achieve rapid detection of the V-shaped crack depth on metal surfaces.To this end,this study investigates the action process of the V-shaped crack and the surface acoustic wave within a certain range and adopts the finite element method to simulate the transmission process of the surface acoustic wave signal excited by the linear pulse laser source in metal materials under the thermoelastic mechanism and the interaction process of surface acoustic wave and Vshaped crack.The study show that V-shaped cracks of different depths and surface acoustic waves have different interaction processes.By analyzing the mechanism of different depth cracks and surface acoustic wave,the crack depth information is divided to three range intervals,and the calculation method of corresponding crack depth is estimated.In accordance with different action processes,this study proposes a rapid judgment and detection method for the V-shaped crack depth on metal surfaces.By detecting the surface acoustic wave reflected echo signal RR and the converted shear wave signal RS peak size,the depth range of the Vshaped crack can be quickly judged,and then its depth information is detected.This method enables rapid location of the crack depth interval and improvement of the detection efficiency of V-shaped crack depth information on metal surfaces.The simulation shows that the error of the crack depth between the calculated value and actual one does not exceed 5%,and that this method can achieve efficient detection of metal surface V-shaped cracks.