scholarly journals Nondestructive Analysis of Debonds in a Composite Structure under Variable Temperature Conditions

Sensors ◽  
2019 ◽  
Vol 19 (16) ◽  
pp. 3454 ◽  
Author(s):  
Shirsendu Sikdar ◽  
Abhishek Kundu ◽  
Michał Jurek ◽  
Wiesław Ostachowicz
Keyword(s):  
Wave Propagation ◽  
Ambient Temperature ◽  
Composite Structure ◽  
Composite Structures ◽  
Variable Temperature ◽  
Guided Wave ◽  
Monitoring Strategy ◽  
Nondestructive Analysis ◽  
Adhesively Bonded ◽  
Temperature Conditions

This paper presents a nondestructive analysis of debonds in an adhesively-bonded carbon-fibre reinforced composite structure under variable temperature conditions. Towards this, ultrasonic guided wave propagation based experimental analysis and numerical simulations are carried out for a sample composite structure to investigate the wave propagation characteristics and detect debonds under variable operating temperature conditions. The analysis revealed that the presence of debonds in the structure significantly reduces the wave mode amplitudes, and this effect further increases with the increase in ambient temperature and debond size. Based on the debond induced differential amplitude phenomenon, an online monitoring strategy is proposed that directly uses the guided wave signals from the distributed piezoelectric sensor network to localize the hidden debonds in the structure. Debond index maps generated from the proposed monitoring strategy show the debond identification potential in the adhesively-bonded composite structure. The accuracy of the monitoring strategy is successfully verified with non-contact active infrared-thermography analysis results. The effectiveness of the proposed monitoring strategy is further investigated for the variable debond size and ambient temperature conditions. The study establishes the potential for using the proposed damage index constructed from the differential guided wave signal features as a basis for localization and characterization of debond damages in operational composite structures.

Effects of debonding on Lamb wave propagation in a bonded composite structure under variable temperature conditions

2018 ◽  
Vol 28 (1) ◽  
pp. 015021 ◽  
Author(s):  
Shirsendu Sikdar ◽  
Piotr Fiborek ◽  
Paweł Kudela ◽  
Sauvik Banerjee ◽  
Wiesław Ostachowicz
Keyword(s):  
Wave Propagation ◽  
Composite Structure ◽  
Lamb Wave ◽  
Variable Temperature ◽  
Temperature Conditions ◽  
Bonded Composite ◽  
Lamb Wave Propagation

scholarly journals Detection of debonding in adhesive joints using Lamb wave propagation

2019 ◽  
Vol 262 ◽  
pp. 10012
Author(s):  
Magdalena Rucka ◽  
Erwin Wojtczak ◽  
Jacek Lachowicz
Keyword(s):  
Wave Propagation ◽  
Lamb Waves ◽  
Visual Assessment ◽  
Guided Wave ◽  
Steel Plates ◽  
Experimental Investigations ◽  
Mechanical Degradation ◽  
Adhesively Bonded ◽  
Destructive Testing ◽  
Out Of Plane

Adhesively bonded joints are widely used in many branches of industry. Mechanical degradation of this type of connections does not have significant symptoms that can be noticed during visual assessment, so non-destructive testing becomes a very important issue. The paper deals with experimental investigations of adhesively bonded steel plates with different defects. Five samples (an intact one and four with damages in the form of partial debonding) were prepared. The inspection was conducted with the use of guided wave propagation method. Lamb waves were excited at one point of the sample, whereas the out-of-plane velocity signals were recorded in a number of points spread over the area of overlap. The processing of signals consisted of calculations of weighted root mean square (WRMS). The results of the analysis showed that the WRMS maps allow for identification and determination of size and shape of debonding areas.

Identification of multi-defects in an arched composite structure by the corrected probabilistic diagnostic imaging with the fused damage index

2021 ◽  
pp. 1045389X2110322
Author(s):  
Hashen Jin ◽  
Jun Li ◽  
Weibin Li ◽  
Xinlin Qing
Keyword(s):  
Diagnostic Imaging ◽  
Composite Structure ◽  
Shape Factor ◽  
Composite Structures ◽  
Damage Index ◽  
Guided Wave ◽  
Identification Accuracy ◽  
Size Information ◽  
Damage Indices ◽  
Ultrasonic Guided Wave

Due to the complicacy of geometry and structure in the arched composite structure, it is difficult to monitor various kinds of defects accurately. The developed damage probabilistic diagnostic imaging approach based on ultrasonic guided wave energy signal characteristics is very feasible for the structural health monitoring in the arched composite structures. However, the conventional probabilistic diagnostic imaging (PDI) approaches united with the signal energy damage indices ( DIs) have some limitations in the identification of the number, location and specific size information of multi-defects. Thus, the damage shape factor from the single damage-impaired path imminently demands to be majorized to raise the precision and stability of PDI approach in the damage recognition. A corrected probabilistic diagnostic imaging (CPDI) approach integrated with the damage shape factor [Formula: see text] needs to be recommended to precisely inspect the expansion of defect zones and different multi-defects in the arched composite structure. The availability and feasibility of the proposed methods has been validated by the experiments in the tested specimen. The results show that the fused frequency-domain energy DIs can be applied to indicate the expansion of defect zones quantitatively. It is proved that the defect identification accuracy of multi-defects from the CPDI approach can be improved by the majorization of damage shape factor, effectively. It is also clearly observed that the number, location and specific size information of different conditions of multi-defects can be distinguished by using the CPDI algorithm, availably.

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