非线性Lamb波脉冲激励的零频分量理论  

The theory of zero frequency component induced by nonlinear Lamb wave pulse

作　　者：孙晓强 张晋源[1] 胡宁 SUN Xiaoqiang;ZHANG Jinyuan;HU Ning(College of General Education,Chongqing Industry Polytechnic College,Chongqing 401120,China;State Key Laboratory of Reliability and Intelligence Electrical Equipment,Hebei University of Technology,Tianjin 300130,China)

机构地区：[1]重庆工业职业技术学院通识教育学院,重庆401120 [2]河北工业大学可靠性与智能化电气装备国家重点实验室,天津300130

出　　处：《河北工业大学学报》2021年第6期1-12,共12页Journal of Hebei University of Technology

基　　金：国家自然科学基金(201430430429);河北省自然科学基金创新研究群体基金(A2020202002);天津市自然科学基金重点项目(S20ZDF077)。

摘　　要：为方便利用非线性Lamb波脉冲激励零频分量进行板材结构早期损伤超声无损健康监测,基于二次材料弱非线性,在基波和零频分量群速度相等的情况下,推导非线性Lamb波脉冲激励零频分量的理论解。以汉宁窗调制的短脉冲激励为例,建立仿真模型,提取仿真零频信号,制作零频信号传播动画,展示对称模态零频分量克服相速匹配条件的限制进而可持续累积的特征。理论仿真结果与分析讨论表明,零频模态为对称模态,零频形貌与窗函数形貌相似,基波群速度失配和色散可以分散零频分量能量进而影响零频形貌,零频分量可持续累积特性不受其影响,与二次谐波和混合波检测技术相比,非线性Lamb波零频分量检测技术具有一定的优势。For the convenience of using nonlinear Lamb wave pulse excitation zero frequency component to monitor plate-like material early stage damage,based on the quadratic weak material nonlinearity,the theoretical solution of zero frequency component induced by nonlinear Lamb wave pulse is derived under the condition that the group velocities of fundamental wave and zero-frequency component are equal.A simulation model is established.A Hanning windowed tone burst signal is adopted as the excitation signal.The propagation animation of zero frequency component is obtained.The limitation of phase-velocity matching is overcome and the energy carried by zero frequency component can accumulated continuously.Theoretical results simulation results and discussion analysis show that the shape of the symmetric mode zero frequency component is similar to the shape of the window function.The shape of zero frequency component is influenced by zero frequency component energy dispersion which induced by the group velocity mismatch and dispersion of the fundamental wave.The sustainable accumulation characteristics of the zero frequency component are not affected.Compared with the second harmonic and mixing wave detection technology,nonlinear Lamb wave zero-frequency component inspection technique has certain advantages.

关 键 词：结构健康监测 非线性Lamb波 零频分量 材料弱非线性 材料早期损伤 

分 类 号：TG115.285[金属学及工艺—物理冶金] TB553[金属学及工艺—金属学]