Research On Damage Detection Technology Of Marine Composite Panel Based On Lamb Wave

The application of composite materials in the marine field continues to increase,which provides higher requirements for the non-destructive testing technology of composite materials.When using Lamb waves to detect damage in the composite structure of ships,the phenomenon that the speed of Lamb waves changes with the direction when propagating in the composite plate and the existence of boundary reflection waves increase the difficulty of detection.This article relies on the Ministry of Industry and Information Technology’s high-tech ship research the project carried out research on the damage detection technology of marine composite panels based on Lamb waves,and provided solutions for the above-mentioned problems.First,the propagation characteristics of Lamb waves in composite plates are studied,the dispersion equation of Lamb waves in composite plates is deduced,the finite element model of Lamb waves propagating in composite plates is established by Abaqus,and A0 and S0 are analyzed.Propagation characteristics of mode Lamb waves in marine composite panels.Secondly,a simulation study on damage detection of composite plates was carried out,using antisymmetric loading to excite a single A0 mode Lamb wave in a marine composite plate,and a method of drawing the dispersion curve using the finite element method was proposed.The influence of damage diameter and depth on Lamb wave damage reflection wave,and the influence of microcrack length and width on Lamb wave nonlinear coefficient are studied respectively.Then,the damage location of the composite plate based on the absorbing boundary was studied.The absorbing boundary was set in the three-dimensional model of the composite plate,and the influence of the maximum damping coefficient and the number of absorbing layers on the absorbing efficiency of the absorbing boundary was studied.Rapid location of damage in the middle.Finally,the damage imaging problem in the composite plate is studied.Aiming at the problem of the anisotropy of the composite plate,the probabilistic imaging algorithm is used to image the damage in the composite plate,and the Lamb wave received signal containing different intensities of noise is signaled.Denoising,the development of the damage detection system is completed by using Lab VIEW.