Title:Theoretical analysis, simulation and experimental observation of nonlinear ultrasonic Lamb wave mixing response
Time:November 29, 2018, 09:30 -11:00 am
Location:Conference Room 530, 5th Floor, Science Building, Fudan University
Speaker: Deng Mingxi(Professor, Doctoral Supervisor, School of Aeronautics and Astronautics, Chongqing University)
Summary：
Based on the nonlinear wave theory and combined with the propagation characteristics of ultrasonic Lamb waves, the acoustic nonlinear response of two Lamb wave modes with different frequencies mixed in a solid plate is studied. Using the guided wave mode expansion analysis method, the nonlinear response characteristics of the second-order, third-order, sum-frequency and difference-frequency harmonics are analyzed, and the fundamental frequency blue of the sum-frequency and difference-frequency harmonics in the aliasing area is given. The selection conditions of the mbo mode and frequency. Through simulation and experimental observation, the influence of mode selection and frequency control on the nonlinear response of Lamb wave beam aliasing is studied. Through theoretical analysis, simulation and experimental observation, this work reveals the physical mechanism of nonlinear ultrasonic Lamb wave mixing response, and provides a basis for the development of nonlinear ultrasonic Lamb wave detection technology based on beam aliasing.
Introduction of reporter:
Deng Mingxi received his bachelor's, master's and doctorate degrees from Sichuan University, Nanjing University and Tongji University. From September 2000 to September 2018, he served as a professor and doctoral supervisor in the School of Logistics Engineering. Now he is a part-time professor of Chongqing University.
Professor Deng Mingxi is the executive director of the Acoustic Society of China, the vice chairman of the Acoustic Society of China Testing Acoustics Branch, the chairman of the Acoustic Society of Chongqing, the new century outstanding talents of the Ministry of Education, the National Natural Science Foundation of China Expert of the 12th and 13th Subject Review Group of the committee, academic member of the Key Laboratory of Modern Acoustics of the Ministry of Education. In 2007, he enjoyed special government allowances and won the military academies' prize for educating talents. In 2010, he was appointed as a distinguished professor of Bayu Scholars in Chongqing Universities.
Professor Deng Mingxi has been engaged in ultrasound research for a long time, and has been responsible for a number of National Natural Science Foundation projects. Published academic monograph "Non-linear Lamb Waves in Solid Plates" in Science Press; published more than 190 academic papers, of which more than 80 were included by SCI and more than 100 by EI. As the project leader, he won 1 second prize of Natural Science Award of Ministry of Education, 1 second prize of Chongqing Natural Science Award, and 2 third prize of Chongqing Science and Technology Progress Award; as the main researcher of the project, he won the National Science and Technology Progress Award 1 second prize, 1 first prize of the Army Science and Technology Progress Award, and 1 first prize of the Shanghai Natural Science Award.
