Strain sensitivity model for guided waves in plates using the time-reversal technique

2013 ◽  
Vol 60 (12) ◽  
pp. 2566-2574 ◽  
Author(s):  
Alan C. Kubrusly ◽  
Nicolas Perez ◽  
Julio C. Adamowski ◽  
Jean Pierre Von Der Weid
Keyword(s):  
Time Reversal ◽  
Guided Waves ◽  
Strain Sensitivity

Numerical Investigation of Nonlinear Lamb Wave Time Reversing for Fatigue Crack Detection

2019 ◽  
Author(s):  
Junzhen Wang ◽  
Yanfeng Shen
Keyword(s):  
Finite Element ◽  
Fatigue Crack ◽  
Time Reversal ◽  
Lamb Wave ◽  
Crack Detection ◽  
Guided Waves ◽  
Fatigue Cracks ◽  
Contact Dynamics ◽  
Virtual Time ◽  
Fatigue Crack Detection

Abstract This paper presents a numerical study on nonlinear Lamb wave time reversing for fatigue crack detection. An analytical framework is initially presented, modeling Lamb wave generation, propagation, wave crack linear and nonlinear interaction, and reception. Subsequently, a 3D transient dynamic coupled-field finite element model is constructed to simulate the pitch-catch procedure in an aluminum plate using the commercial finite element software (ANSYS). The excitation frequency is carefully selected, where only single Lamb wave mode will be generated by the Piezoelectric Wafer Active Sensor (PWAS). The fatigue cracks are modelled nucleating from both sides of a rivet hole. In addition, contact dynamics are considered to capture the nonlinear interactions between guided waves and the fatigue cracks, which would induce Contact Acoustic Nonlinearity (CAN) into the guided waves. Then the conventional and virtual time reversal methods are realized by finite element simulation. Advanced signal processing techniques are used to extract the distinctive nonlinear features. Via the Fast Fourier Transform (FFT) and time-frequency spectral analysis, nonlinear superharmonic components are observed. The reconstructed signals attained from the conventional and virtual time reversal methods are compared and analyzed. Finally, various Damage Indices (DIs), based on the difference between the reconstructed signal and the excitation waveform as well as the amplitude ratio between the superharmonic and the fundamental frequency components are adopted to evaluate the fatigue crack severity. The DIs could provide quantitative diagnostic information for fatigue crack detection. This paper finishes with summary, concluding remarks, and suggestions for future work.

Time Reversal Technique for Ultrasonic Guided Wave Inspection

2006 ◽  
Vol 321-323 ◽  
pp. 776-779
Author(s):  
Hak Joon Kim ◽  
Sung Jin Song ◽  
Jung Ho Seo ◽  
Jae Hee Kim ◽  
Heung Seop Eom
Keyword(s):  
Time Delay ◽  
Power Plant ◽  
Time Reversal ◽  
Nuclear Power ◽  
Guided Waves ◽  
Performance Enhancement ◽  
Guided Wave ◽  
Ultrasonic Waves ◽  
Ultrasonic Guided Waves ◽  
Ultrasonic Guided Wave

For the long range inspection of structures in nuclear power plant using array transducers, it is necessary to focus waves on defects under interrogation. To take care of such a need, in this study we adopt a time reversal technique that is claimed to be very robust to focus ultrasonic waves on defects. Specifically, we calculate the appropriate time delay using the time reversal technique and re-generate ultrasonic guided waves that are focusing to an interrogated defect with the calculated time delay. In this paper, we describe the principle of the time reversal technique briefly and present the performance enhancement obtained by the time reversal techniques.

Guided wave time-reversal imaging of macroscopic localized inhomogeneities in anisotropic composites

2019 ◽  
Vol 18 (5-6) ◽  
pp. 1803-1819 ◽  
Author(s):  
Artem Eremin ◽  
Evgeny Glushkov ◽  
Natalia Glushkova ◽  
Rolf Lammering
Keyword(s):  
Time Reversal ◽  
Guided Waves ◽  
Laminate Plate ◽  
Composite Plates ◽  
Metal Plate ◽  
Guided Wave ◽  
Integral Representations ◽  
Computational Time ◽  
Source Characterization ◽  
Reconstruction Procedure

Estimation of damage position and extent in the inspected structure is among the emerging problems of active structural health monitoring (SHM) with elastic guided waves. Unlike conventional non-destructive testing (NDT) techniques, which assume continuous surface scanning, SHM systems operate only with data from a limited number of sensors. Nevertheless, in the case of isotropic (metal) plate-like structures, computational time-reversal techniques have proved to be effective for estimating in situ the location and size of wave sources and/or local scatterers within the SHM concept. With composite plates, the reconstruction procedure faces additional difficulties associated with the complexity of wave phenomena caused by their lamination and anisotropy. In this article, we present an extension of the time reversal technique for the case of composite laminate plate-like structures. This technique relies on the simulation of the reversed guided waves generated by reciprocal surface loads applied at a sparse set of measurement points of a real sensor network. The proposed implementation is based on the far-field asymptotics for guided waves generated in arbitrarily anisotropic laminate waveguides by a prescribed source, which have been derived from the path integral representations in terms of Green’s matrix for the structures considered. The performance of this approach has been experimentally tested on cross-ply carbon fiber-reinforced plastic plates showing reliable and adequate results for both active (piezoactuators) and passive (artificial defects) source characterization.

A Study on the Time Reversal Method for Focusing Ultrasonic Guided Waves Using Array Transducers

2007 ◽  
Author(s):  
Hak-Joon Kim ◽  
Jong-Ho Seo ◽  
Sung-Jin Song ◽  
Jae-Hee Kim ◽  
Heung-Seop Eom
Keyword(s):  
Time Reversal ◽  
Guided Waves ◽  
Ultrasonic Guided Waves
Sign in / Sign up

Export Citation Format

Share Document