Research progress of acoustic emission detection technology based on modal theory

The essence of modal acoustic emission theory is to study acoustic emission waves using Lamb wave theory. Different from the traditional acoustic emission research, the modal acoustic emission analyzes the entire waveform of the signal received by the sensor, distinguishes various modal waves in the composite material, and improves the detection accuracy of the composite material. At present, the research on acoustic emission technology of composite materials at home and abroad mainly focuses on five aspects of Lamb wave dispersion characteristics, finite element simulation of defect detection, experimental system design, time-frequency analysis of Lamb wave signal, damage location and damage imaging. From these five aspects, the research progress of the composite defect nondestructive testing technology is reviewed, and the problems to be further solved are put forward.