中国物理B ›› 2020, Vol. 29 ›› Issue (5): 54301-054301.doi: 10.1088/1674-1056/ab81f7
• ELECTROMAGNETISM, OPTICS, ACOUSTICS, HEAT TRANSFER, CLASSICAL MECHANICS, AND FLUID DYNAMICS • 上一篇 下一篇
Yaoxin Liu(刘尧鑫), Aijun He(何爱军), Jiehui Liu(刘杰惠), Yiwei Mao(毛一葳), Xiaozhou Liu(刘晓宙)
Yaoxin Liu(刘尧鑫)1, Aijun He(何爱军)3, Jiehui Liu(刘杰惠)1, Yiwei Mao(毛一葳)1, Xiaozhou Liu(刘晓宙)1,2
摘要: A promising tool to detect micro-cracks in plate-like structures is used for generating higher harmonic Lamb waves. In this paper, a method combining nonlinear S0 mode Lamb waves with time reversal to locate micro-cracks is presented and verified by numerical simulations. Two different models, the contact acoustic nonlinearity (CAN) model and the Preisach-Mayergoyz (PM) model, are used to simulate a localized damage in a thin plate. Pulse inversion method is employed to extract the second and fourth harmonics from the received signal. Time reversal is performed to compensate the dispersion of S0 mode Lamb waves. Consequently, the higher harmonics generated from the damaged area can be refocused on their source. By investigating the spatial distribution of harmonic wave packets, the location of micro-cracks will be revealed. The numerical simulations indicate that this method gives accurate locations of the damaged area in a plate. Furthermore, the PM model is proved to be a suitable model to simulate the micro-cracks in plates for generation of higher harmonics.
中图分类号: (Nonlinear acoustics of solids)