Ding Xiangyan, Zhao Youxuan, Hu Ning, Liu Yaolu, Zhang Jun, Deng Mingxi
College of Aerospace Engineering, Chongqing University, Chongqing 400044, China.
State Key Laboratory of Coal Mine Disaster Dynamics and Control, Chongqing University, Chongqing 400044, China.
Materials (Basel). 2018 Oct 25;11(11):2096. doi: 10.3390/ma11112096.
This paper investigates the propagation of low-frequency ₀ mode Lamb waves in plates with quadratic nonlinearity through numerical simulations and experimental measurements. Both numerical and experimental results manifest distinct ultrasonic nonlinear behavior which is mainly presented by the second harmonics. Meanwhile, we find that both the acoustic nonlinearity parameter and dispersion distance show the exponential decay trend with the increase of frequency-thickness. Moreover, the results reveal that the frequency is key to affect the acoustic nonlinearity parameter and dispersion distance with the same frequency-thickness. This study theoretically and experimentally reveals that nonlinear Lamb waves of the low-frequency ₀ mode are feasible to quantitatively identify material weak nonlinearity in plates.
本文通过数值模拟和实验测量研究了具有二次非线性的板中低频零阶兰姆波的传播特性。数值和实验结果均表明存在明显的超声非线性行为，主要表现为二次谐波。同时，我们发现声学非线性参数和色散距离均随频率厚度的增加呈指数衰减趋势。此外，结果表明在相同频率厚度下，频率是影响声学非线性参数和色散距离的关键因素。本研究从理论和实验上揭示了低频零阶非线性兰姆波在定量识别板中材料弱非线性方面的可行性。
