Guided Lamb waves for identification of damage in composite structures: A review

2006 ◽  
Vol 295 (3-5) ◽  
pp. 753-780 ◽  
Author(s):  
Zhongqing Su ◽  
Lin Ye ◽  
Ye Lu
Keyword(s):  
Composite Structures ◽  
Lamb Waves

The Effect of Ply Orientation and Damage Detection in Composite Stiffened Panel Using Lamb Waves

2019 ◽  
Vol 298 ◽  
pp. 161-166
Author(s):  
Ouadia Mouhat ◽  
Abdelmajid Bybi ◽  
Ahmed El Bouhmidi ◽  
Hasnae Boubel ◽  
Omaima Elmrabet ◽  
...  
Keyword(s):  
Acoustic Waves ◽  
Composite Structures ◽  
Laminate Composite ◽  
Lamb Waves ◽  
Stiffened Panel ◽  
Signal Acquisition ◽  
Frequency Increase ◽  
Stiffened Panels ◽  
Composite Stiffened Panel ◽  
Ply Orientation

The present work proposes a vibration study with different surface and layers orientations at 0°, 15°, 30°, 45°, 60°, 75° and 90°using the Abaqus finite element code, the frequencies Stratified laminate composite panels were studied and the comparison between damaged structures and perfect structures we used stiffened panels based on T-shaped reinforced fibers. Lamb waves (LW) were widely proposed for the long-range inspection of Structural Structural Health Monitoring (SHM) oriented composite structures, the obtained results show the angle effects on the natural frequency increase at a peak then decrease in the form of a sinusoidal half-curve and the numerical results found in this work can be compared to those of other authors in the same area of ​​research, A piezoelectric actuator is used to design acoustic waves and a sensor is used for signal acquisition.

scholarly journals Impact Localisation in Composite Plates of Different Stiffness Impactors under Simulated Environmental and Operational Conditions

Sensors ◽  
2019 ◽  
Vol 19 (17) ◽  
pp. 3659 ◽  
Author(s):  
Seno ◽  
Aliabadi
Keyword(s):  
Composite Structures ◽  
Lamb Waves ◽  
Real Life ◽  
Composite Plates ◽  
Information Criterion ◽  
Reference Database ◽  
Time Of Arrival ◽  
Operational Conditions ◽  
Contact Behaviour ◽  
Using Data

A parametric investigation of the effect of impactor stiffness as well as environmental and operational conditions on impact contact behaviour and the subsequently generated lamb waves in composite structures is presented. It is shown that differing impactor stiffness generates the most significant changes in contact area and lamb wave characteristics (waveform, frequency, and amplitude). A novel impact localisation method was developed based on the above observations that allows for variations due to differences in impactor stiffness based on modifications of the reference database method and the Akaike Information Criterion (AIC) time of arrival (ToA) picker. The proposed method was compared against a benchmark method based on artificial neural networks (ANNS) and the normalised smoothed envelope threshold (NSET) ToA extraction method. The results indicate that the proposed method had comparable accuracy to the benchmark method for hard impacts under various environmental and operational conditions when trained only using a single hard impact case. However, when tested with soft impacts, the benchmark method had very low accuracy, whilst the proposed method was able to maintain its accuracy at an acceptable level. Thus, the proposed method is capable of detecting the location of impacts of varying stiffness under various environmental and operational conditions using data from only a single impact case, which brings it closer to the application of data driven impact detection systems in real life structures.

Improved elliptical triangulation method for damage detection in composite material structures

2016 ◽  
Vol 231 (16) ◽  
pp. 3011-3023 ◽  
Author(s):  
Assunta Sorrentino ◽  
Angelo De Fenza
Keyword(s):  
Composite Material ◽  
Damage Detection ◽  
Composite Structures ◽  
Lamb Waves ◽  
Propagation Speed ◽  
Main Research ◽  
Detection Techniques ◽  
Triangulation Method ◽  
Wave Propagation Speed ◽  
Main Research Topic

In this paper, an improvement of the elliptical triangulation method for damage detection using Lamb waves is presented. The damage is the main cause of structural failure and often occurs on structures. In order to avoid sudden failure, a special attention was given in the past decades to the damage detection in structures. In order to obtain efficient damage detection techniques, the structural health monitoring has been the main research topic of many scientists worldwide. The elliptical triangulation method, proposed in this paper, is a non-destructive method based on measurement of Lamb waves. This method, through the calculation of the time of flight of the signals and the actuator-sensor positioning, allows to identify position and dimension of the damage. The application of the method to the metallic structures and to the composite material structures is presented in this paper. The complexity connected with the uncertainty of the waves’ propagation speed due to the anisotropy of the composite materials has been explored through an iterative approach. The initialization of the wave propagation speed at first tentative iteration is the key issue for the convergence of the method. Seven different conditions were used to validate the method on both metallic and composite structures combining two damage shapes, two damage dimensions (effective damaged area), and three different positions. Upon evaluating the effectiveness, the method has been applied at two composite panels in order to detect by test the post-impact damages. Tests results have been compared with the numerical ones. The feasibility of the elliptical triangulation method to detect the damage (evaluating the damage position and area) has been proved using the ultrasonic C-Scan.

A Numerical Approach for the Investigation of Guided-Waves Propagation Mechanisms in Reinforced Polymers through a DoE Analysis

2019 ◽  
Vol 957 ◽  
pp. 329-339
Author(s):  
A. de Luca ◽  
Donato Perfetto ◽  
Francesco Caputo
Keyword(s):  
Material Properties ◽  
Composite Structures ◽  
Guided Waves ◽  
Lamb Waves ◽  
Numerical Models ◽  
Detection Sensitivity ◽  
Fe Model ◽  
Structural Health ◽  
Waves Propagation ◽  
Local Material Properties

Thanks to their high damage detection sensitivity and low requested power consumption, guided-waves (Lamb waves) have been increasingly used in the last years to monitor the structural integrity in primary and secondary composite structures. The monitoring of the structural health through the propagation of Lamb waves in composite structures is notoriously complex and, for this reason, the development of a prediction model can be a helpful tool for the improvement of Structural Health Monitoring (SHM) systems. Finite Element Method (FE) appears to be the best candidate for such type of simulation. However, since Lamb waves propagation depends strictly on the local material properties of the medium they propagate through, their numerical characterization is a thorny phase. Real composite components are usually affected by the presence of a large number of voids and defects, which cannot be reproduced in numerical models; this leads to a variability of the mechanical properties of materials, with particular reference to elastic moduli and density. These aspects get really ambitious the development of a well-established FE model. In this paper, a design of experiment (DOE) has been carried out to numerically investigate on the effects of the material properties variability on guided-waves time of flight.

Delamination detection in composite structures using laser vibrometer measurement of Lamb waves

2010 ◽  
Author(s):  
Hoon Sohn ◽  
Eric D. Swenson ◽  
Steven E. Olson ◽  
Martin P. DeSimio ◽  
Debaditya Dutta
Keyword(s):  
Composite Structures ◽  
Lamb Waves ◽  
Laser Vibrometer ◽  
Delamination Detection

A Compensation Method for Environmental Influences on Passive Lamb Wave Based Impact Evaluation for CFRP

2013 ◽  
Vol 569-570 ◽  
pp. 1265-1272 ◽  
Author(s):  
Konstantin Jonas Schubert ◽  
Axel Siegfried Herrmann
Keyword(s):  
Lamb Wave ◽  
Composite Structures ◽  
Lamb Waves ◽  
Detection System ◽  
Main Idea ◽  
Impact Event ◽  
Active System ◽  
Low Velocity ◽  
Temperature Changes ◽  
The Impact

One of the largest issues remaining on the way to in situ Structural Health Monitoring of composite structures using Lamb waves is the impact that non-damaging factors like temperature changes and humidity absorption have on most measurement strategies. While some of these tasks have been successfully conquered, others, especially related to slowly developing influences like humidity absorption or mechanical ageing, remain challenging. In this paper, a method to approach this problem for a Lamb-wave based passive impact detection system is presented. Passive approaches use the waves generated by the impact event itself to both localize said event and evaluate whether it was large enough to damage the structure. For this, the impacts energy has to be estimated from sensors detecting the Lamb waves. The problem provided by changing conditions within the material is that the locally measurable wave amplitude due to an impact event of a certain energy is altered if the material properties change. This might happen due to temperature changes, mechanical loads, humidity absorption, fluid loads and other factors. The main idea of the presented approach is to mix a passive and an active system. Piezoelectric elements are used to generate Lamb waves to obtain the attenuation coefficients of the material before and after hot/wet-conditioning. These coefficients are then used to estimate the impact energy from passive sensor responses. Both the approach and experimental validation performed with low velocity impacts from an impact hammer are presented to show the ability to correctly calculate impact forces after conditioning.

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