激光阵列用于铝板表面裂纹探测的数值模拟  

Numerical Simulation of Laser Arrays for Surface Crack Detection on Aluminum Plate

作　　者：金桢玥 张兴媛[1] 陆思烨 郭明泽 Jin Zhenyue;Zhang Xingyuan;Lu Siye;Guo Mingze(Air Transport College,Shanghai University of Engineering Science,Shanghai 201620,China)

机构地区：[1]上海工程技术大学航空运输学院,上海201620

出　　处：《应用激光》2024年第11期129-140,共12页Applied Laser

基　　金：中国民航大学省部级科研机构开放基金(2021ASP-TJ01)。

摘　　要：为利用激光阵列源检测铝板表面裂纹信息,采用有限元方法(COMSOL)分别模拟单脉冲线源和激光阵列源各自作用时,表面波与铝板表面裂纹间相互作用的物理过程。基于热弹机制,分别构建单脉冲线源和激光阵列源辐照铝板表面激发表面波的有限元模型,对比两者数值模拟的结果。激光阵列源作用时,对表面波与铝板表面不同深度裂纹相互作用的物理过程进行数值模拟,并对比各个阵元的激光源激发得到的信号图;不同线半宽的激光阵列源作用时,对比其激发得到的表面波幅值图与频谱图,研究不同线半宽的激光阵列源激发得到的表面波探测深度。结果表明,随着激光阵列源阵元数目的增加,时间调制后表面波的幅值会随之变化,表面波信号幅值与激光阵列源的阵列元数目成正比例关系,表面波的幅值进行了累加。随着激光阵列源线半宽的增加,其激发出来的表面波波长增加,其探测裂纹深度的范围会增加。In order to detect the surface crack information of aluminum plate using laser array source,the physical process of the interaction between Rayleigh wave and surface crack of aluminum plate is simulated by finite element method(COMSOL)in this paper when the single-pulse line source and laser array source are acting separately.Based on the thermoelastic mechanism,finite element models are constructed for the excitation of Rayleigh waves on the surface of aluminum plate irradiated by single-pulse line source and laser array source respectively,and the results of both numerical simulation are compared.The physical processes of Rayleigh wave interaction with cracks at different depths on the surface of the aluminum plate are simulated numerically when the laser array source acts,and the signals obtained from laser array sources of each array element are compared;when laser array sources with different line half-widths act,the amplitude and spectra of Rayleigh wave obtained from the excitation of them are compared,and the detection depths of the Rayleigh waves obtained from the excitation of laser array sources with different line half-widths are studied.The findings indicate that the amplitude of the Rayleigh wave changes post-time modulation with an increase in the number of array elements,and the amplitude is proportional to the number of array elements from the laser array source,suggesting a cumulative effect on the Rayleigh wave amplitude.An increase in the half-width of the laser array source line results in an increase in the Rayleigh wave wavelength and an expanded range of crack depth detection.

关 键 词：激光阵列 表面裂纹 热弹机制 有限元仿真 

分 类 号：TG146.21[一般工业技术—材料科学与工程] TG115.28[金属学及工艺—金属材料]