A More Accurate Reconstruction Method for Detecting Large-Depth Defects in Plates Using SH Guided Waves

作     者：Yihui Da Qi Li Bin Wang Dianzi Liu Zhenghua Qian Yihui Da;Qi Li;Bin Wang;Dianzi Liu;Zhenghua Qian

作者机构：State Key Laboratory of Mechanics and Control of Mechanical StructuresCollege of Aerospace EngineeringNanjing University of Aeronautics and AstronauticsNanjing210016China School of EngineeringUniversity of East AngliaNorwich NR47TJUK 

出 版 物：《Acta Mechanica Solida Sinica》 (固体力学学报（英文版）)

年 卷 期：2021年第34卷第2期

页      面：174-183页

核心收录：

学科分类：08[工学] 0805[工学-材料科学与工程（可授工学、理学学位）] 0802[工学-机械工程] 0701[理学-数学] 0801[工学-力学（可授工学、理学学位）] 080102[工学-固体力学] 0702[理学-物理学] 

基　　金：supported in part by the State Key Laboratory of Mechanics and Control of Mechanical Structures at NUAA[Grant Number MCMS-E-0520K02] in part by the Key Laboratory of impact and Safety Engineering,Ministry of Education,Ningbo University[CJ201904] in part by the National Natural Science Foundation of China[Grant Numbers 11502108,1611530686]. 

主　　题：Large-depth defect SH guided wave Iterative strategy Reference model Hybrid FEM 

摘      要：The inspection of thickness thinning defects and corrosion defects is greatly significant for the health prediction of plate structures.The main aim of this research is to propose a novel and effective approach to achieve the accurate and rapid detection of arbitrary defects using shear horizontal(SH)guided waves,particularly for large-depth and complex defects.The proposed approach combines the quantitative detection of Fourier transform with a reference model-based strategy to improve the accuracy of large-depth defect detection.Since the shallow defect profile is theoretically constructed by inverse Fourier transform of the product of reflection coefficients and integral coefficients of reference models,the unknown large-depth defect can be initially assessed using the relevant information from a predefined reference model.By iteratively updating the integral coefficients of reference models,the accuracy of reconstruction of large-depth defects is much improved.To achieve the converged defect profile,a termination criterion,the root mean square error,is applied to guarantee the construction of defects with a high level of accuracy.Moreover,the hybrid finite element method is used to simulate the propagation of SH guided waves in plates for calculating the reflection coefficients of plates with defects.Finally,to demonstrate the capability of the developed reconstruction method for defect detection in terms of accuracy and efficiency,three types of large-depth defect profiles,i.e.,a rectangular flaw,a double-rectangular flaw and a complex flaw,are examined.Results show that the discrepancy between the predicted defect profile and the real one is quite small,even in the largest-depth defect case where the defect depth is equal to 0.733 times the plate thickness,the minimal difference is observed.It is noted that the fast convergence of the proposed approach can be achieved by no more than ten updates for the worst case.