scholarly journals Ultrasonic based structural damage detection using combined finite element and model Lamb wave propagation parameters in composite materials

2012 ◽  
Vol 67 (5-8) ◽  
pp. 1847-1856 ◽  
Author(s):  
B. S. Ben ◽  
S. H. Yang ◽  
Ch. Ratnam ◽  
B. A. Ben
Keyword(s):  
Finite Element ◽  
Wave Propagation ◽  
Composite Materials ◽  
Damage Detection ◽  
Lamb Wave ◽  
Structural Damage ◽  
Structural Damage Detection ◽  
Propagation Parameters ◽  
Lamb Wave Propagation

Structural damage detection using combined finite-element and model Lamb wave propagation parameters

2008 ◽  
Vol 223 (3) ◽  
pp. 769-777 ◽  
Author(s):  
C Ratnam ◽  
B S Ben ◽  
B A Ben
Keyword(s):  
Finite Element ◽  
Wave Propagation ◽  
Lamb Wave ◽  
Structural Damage ◽  
Pulse Generator ◽  
Ultrasonic Pulse ◽  
Element Analysis ◽  
Propagation Parameters ◽  
Set Up ◽  
Lamb Wave Propagation

This article presents a combined finite-element and model Lamb wave propagation parameters method for structural health monitoring. Modal analysis allows identifying the mode conversions induced by the defects. A simulation combining a planar, lossless finite-element analysis with Lamb wave propagation parameter is proposed. This analysis is performed on two aluminium bars in both undamaged and damaged states, where the two damaged states are: (a) one having a circular hole and (b) the other having a cut partway through the bar, perpendicular to the long axis of the bar. The Lamb wave propagation parameters are calibrated by using the ultrasonic pulse generator test set-up. The natural frequencies for the theoretical, finite element and experimental results are compared, and close agreement is found between the frequencies obtained experimentally and computationally.

Impact of Changing Temperature on Lamb Wave Propagation for Damage Detection

2013 ◽  
Vol 588 ◽  
pp. 140-148 ◽  
Author(s):  
Rafal Radecki ◽  
Wieslaw Jerzy Staszewski ◽  
Tadeusz Uhl
Keyword(s):  
Wave Propagation ◽  
Damage Detection ◽  
Lamb Wave ◽  
Structural Damage ◽  
Clustering Algorithm ◽  
Lamb Waves ◽  
Ultrasonic Waves ◽  
Effect Of Temperature ◽  
Propagation Parameters ◽  
Lamb Wave Propagation

Lamb waves are the most widely used guided ultrasonic waves for structural damage detection. One of the major problems associate with Lamb wave propagation is the effect of temperature on wave propagation parameters. It is important that these parameters are more sensitive to damage than to varying temperature. The paper demonstrates how amplitude and arrival time of Lamb waves are affected by temperature. The analysis is performed for the experimental data gathered from Lamb wave propagation in a damaged aluminium plate. A simple clustering algorithm is used to distinguish between "undamaged" and "damaged" conditions in the presence of changing temperature.

scholarly journals Lamb Wave Based Structural Damage Detection Using Stationarity Tests

Materials ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 6823
Author(s):  
Phong B. Dao ◽  
Wieslaw J. Staszewski
Keyword(s):  
Damage Detection ◽  
Unit Root ◽  
Lamb Wave ◽  
Structural Damage ◽  
Lamb Waves ◽  
Structural Damage Detection ◽  
Kpss Test ◽  
Wave Data ◽  
Lamb Wave Propagation ◽  
Adf Test

Lamb waves have been widely used for structural damage detection. However, practical applications of this technique are still limited. One of the main reasons is due to the complexity of Lamb wave propagation modes. Therefore, instead of directly analysing and interpreting Lamb wave propagation modes for information about health conditions of the structure, this study has proposed another approach that is based on statistical analyses of the stationarity of Lamb waves. The method is validated by using Lamb wave data from intact and damaged aluminium plates exposed to temperature variations. Four popular unit root testing methods, including Augmented Dickey–Fuller (ADF) test, Kwiatkowski–Phillips–Schmidt–Shin (KPSS) test, Phillips–Perron (PP) test, and Leybourne–McCabe (LM) test, have been investigated and compared in order to understand and make statistical inference about the stationarity of Lamb wave data before and after hole damages are introduced to the aluminium plate. The separation between t-statistic features, obtained from the unit root tests on Lamb wave data, is used for damage detection. The results show that both ADF test and KPSS test can detect damage, while both PP and LM tests were not significant for identifying damage. Moreover, the ADF test was more stable with respect to temperature changes than the KPSS test. However, the KPSS test can detect damage better than the ADF test. Moreover, both KPSS and ADF tests can consistently detect damages in conditions where temperatures vary below 60 °C. However, their t-statistics fluctuate more (or less homogeneous) for temperatures higher than 65 °C. This suggests that both ADF and KPSS tests should be used together for Lamb wave based structural damage detection. The proposed stationarity-based approach is motivated by its simplicity and efficiency. Since the method is based on the concept of stationarity of a time series, it can find applications not only in Lamb wave based SHM but also in condition monitoring and fault diagnosis of industrial systems.

Application of Phased Array Antenna Technique in Structural Damage Detection

2011 ◽  
Vol 368-373 ◽  
pp. 1667-1671
Author(s):  
Yu Zhang ◽  
Long Yu ◽  
Yun Ju Yan ◽  
Yu Guo
Keyword(s):  
Wave Propagation ◽  
Damage Detection ◽  
Structural Damage ◽  
Phased Array ◽  
Tone Burst ◽  
Array Antenna ◽  
Detection Accuracy ◽  
Structural Damage Detection ◽  
Phased Array Antenna ◽  
Energy Leakage

Over decades phased array antenna technique attracts much more attention in Lamb wave based structural damage detection. Lamb wave generated by the piezoelectric wafers omnidirectionally could be steered at a specific direction during its propagation. Thus, the wave beam steering and focusing has been established, the location of structural damage is done with pulse-echo method by wave propagation. However, the detection accuracy will decrease as side bands energy leakage during wave propagation, so, signals to be generated have to be modified by window tone burst in order to concentrate energy in main bands and minimize the effect of dispersion side bands. In this paper, signals modified by Hanning-windowed tone burst was used to decrease the effect of side bands energy leakage, the results improved the detection accuracy better than signals without window tone burst and show good agreement with theoretical results. Meanwhile, A numerical simulation of aluminium plate demonstrates that phased array antenna technique is feasible in structural damage detection.

Photogrammetry-based structural damage detection by tracking a visible laser line

2019 ◽  
Vol 19 (1) ◽  
pp. 322-336 ◽  
Author(s):  
Yongfeng Xu
Keyword(s):  
Finite Element ◽  
Damage Detection ◽  
Structural Damage ◽  
Detection Method ◽  
Element Model ◽  
Target Line ◽  
Laser Line ◽  
Modal Parameters ◽  
Structural Damage Detection ◽  
Visible Laser

Research works on photogrammetry have received tremendous attention in the past few decades. One advantage of photogrammetry is that it can measure displacement and deformation of a structure in a fully non-contact, full-field manner. As a non-destructive evaluation method, photogrammetry can be used to detect structural damage by identifying local anomalies in measured deformation of a structure. Numerous methods have been proposed to measure deformations by tracking exterior features of structures, assuming that the features can be consistently identified and tracked on sequences of digital images captured by cameras. Such feature-tracking methods can fail if the features do not exist on captured images. One feasible solution to the potential failure is to artificially add exterior features to structures. However, painting and mounting such features can introduce unwanted permanent surficial modifications, mass loads, and stiffness changes to structures. In this article, a photogrammetry-based structural damage detection method is developed, where a visible laser line is projected to a surface of a structure, serving as an exterior feature to be tracked; the projected laser line is massless and its existence is temporary. A laser-line-tracking technique is proposed to track the projected laser line on captured digital images. Modal parameters of a target line corresponding to the projected laser line can be estimated by conducting experimental modal analysis. By identifying anomalies in curvature mode shapes of the target line and mapping the anomalies to the projected laser line, structural damage can be detected with identified positions and sizes. An experimental investigation of the damage detection method was conducted on a damaged beam. Modal parameters of a target line corresponding to a projected laser line were estimated, which compared well with those from a finite element model of the damaged beam. Experimental damage detection results were validated by numerical ones from the finite element model.

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