Lamb-Wave-Based Damage Identification in Laminated Composite Plates

With advantages including capability of propagation over a significant distance and high sensitivity to abnormalities and inhomogeneity near the wave propagation path, Lamb waves can be energised to disseminate in a structure and any changes in material properties or structural geometry created by a discontinuity, boundary or structural damage can be identified by examining the scattered wave signals. This paper presents an overview of the Lamb-wave-based damage identification in laminated composite plates including the formulation of lamb waves in an isotropic plate.

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Various types of defects detection in flat and curved laminated composite plates using nonintrusive Lamb wave system

Journal of Nondestructive Evaluation Diagnostics and Prognostics of Engineering Systems ◽

10.1115/1.4049468 ◽

2020 ◽

pp. 1-18

Author(s):

Lingyu Yu ◽

Zhaoyun Ma

Keyword(s):

Lamb Wave ◽

Composite Structures ◽

Lamb Waves ◽

Laminated Composite ◽

Composite Plates ◽

Multidimensional Data ◽

Laser Vibrometer ◽

Wave System ◽

Laminated Composite Plates ◽

Data Acquisition And Processing

Abstract Composite materials are widely used in aerospace industries due to their light weight, strength, and various other desired properties. However, they are susceptible to various defects occurring during the manufacturing process or in service. Typical defects include porosity, wrinkles, and delamination. Nondestructive means of detection of the defects at any stage are of great importance to ensure quality and safety of composite structures. A nonintrusive removable Lamb wave system and accompanied methodology that is not material-dependent is presented in this paper to detect various types of typical defects in laminated composite plates, flat or curved. Through multidimensional data acquisition and processing, abnormality in waves caused by defects is captured and presented in inspection images. The methodologies are demonstrated in 2 cases: delamination in a curved plate, and wrinkles in a flat plate. Overall the results show that Lamb waves using the piezoelectric transducer and laser vibrometer system can be used for various types of defects inspection in flat or curved composite plates.

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Determination of Vibration Source Locations in Laminated Composite Plates Using Lamb Wave Analysis

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.123-125.899 ◽

2010 ◽

Vol 123-125 ◽

pp. 899-902

Author(s):

Chao Du ◽

Qing Qing Ni ◽

Toshiaki Natsuki

Keyword(s):

Lamb Wave ◽

Guided Waves ◽

Lamb Waves ◽

Laminated Composite ◽

Composite Plates ◽

Wave Dispersion ◽

Laminated Plates ◽

Vibration Source ◽

Arrival Times ◽

Wave Velocities

Signals propagate on plate-like structures as ultrasonic guided waves, and analysis of Lamb waves has been widely used for on-line monitoring. In this study, the wave velocities of symmetric and anti-symmetric modes in various directions of propagation were investigated. Since the wave velocities of these two modes are different, it is possible to compute the difference in their arrival times when these waves propagated the distance from the vibration source to sensor. This paper presents an evaluation formulation of wave velocity and describes a generalized algorithm for locating a vibration source on a thin, laminated plate. With the different velocities of two modes based on Lamb wave dispersion, the method uses two sensors to locate the source on a semi-infinite interval of a plate. The experimental procedure supporting this method employs pencil lead breaks to simulate vibration sources on quasi-isotropic and unidirectional laminated plates. The transient signals generated in this way are transformed using a wavelet transform. The vibration source locations are then detected by utilizing the distinct wave velocities and arrival times of the symmetric and anti-symmetric wave modes. The method is an effective technique for identifying impact locations on plate-like structures.

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Damage localization in cross-ply laminated composite plates under varying temperature conditions using Lamb waves

Measurement Science and Technology ◽

10.1088/1361-6501/ab6eca ◽

2020 ◽

Vol 31 (6) ◽

pp. 064003 ◽

Cited By ~ 1

Author(s):

Anvesh R Nandyala ◽

Ashish K Darpe ◽

Satinder P Singh

Keyword(s):

Lamb Waves ◽

Laminated Composite ◽

Composite Plates ◽

Damage Localization ◽

Laminated Composite Plates ◽

Temperature Conditions

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Lamb waves in laminated composite plates

The Journal of the Acoustical Society of America ◽

10.1121/1.2021969 ◽

1984 ◽

Vol 76 (S1) ◽

pp. S66-S66

Author(s):

D. E. Chimenti ◽

Adnan H. Nayfeh

Keyword(s):

Lamb Waves ◽

Laminated Composite ◽

Composite Plates ◽

Laminated Composite Plates

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Non-Model-Based Identification of Delamination in Laminated Composite Plates Using a Continuously Scanning Laser Doppler Vibrometer System

Journal of Vibration and Acoustics ◽

10.1115/1.4038734 ◽

2018 ◽

Vol 140 (4) ◽

Cited By ~ 10

Author(s):

Da-Ming Chen ◽

Y. F. Xu ◽

W. D. Zhu

Keyword(s):

Composite Structure ◽

Composite Plate ◽

Structural Damage ◽

Laser Doppler Vibrometer ◽

Laminated Composite ◽

Composite Plates ◽

Scanning Laser ◽

Laminated Composite Plates ◽

Scanning Laser Doppler Vibrometer ◽

Local Anomalies

Delamination frequently occurs in a laminated composite structure and can cause prominent local anomalies in curvature vibration shapes associated with vibration shapes of the composite structure. Spatially dense vibration shapes of a structure can be rapidly obtained by use of a continuously scanning laser Doppler vibrometer (CSLDV) system, which sweeps its laser spot over a vibrating surface of the structure. This paper introduces a continuous scanning scheme for general quadrangular scan areas assigned on plates and extends two damage identification methods for beams to identify delamination in laminated composite plates using a CSLDV system. One method is based on the technique that a curvature vibration shape from a polynomial that fits a vibration shape of a damaged structure can well approximate an associated curvature vibration shape of an undamaged structure and local anomalies caused by structural damage can be identified by comparing the curvature vibration shape of the damaged structure with that from the polynomial fit, and the other is based on the technique that a continuous wavelet transform can directly identify local anomalies in a curvature vibration shape caused by structural damage. The two methods yield corresponding damage indices and local anomalies in curvature vibration shapes can be identified in neighborhoods with high damage index values. Both numerical and experimental investigations on effectiveness of the two methods are conducted on a laminated composite plate with a delamination area. In the experimental investigation, delamination identification results from the two methods were compared with that from a C-scan image of the composite plate.

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Interpretable convolutional sparse coding method of Lamb waves for damage identification and localization

Structural Health Monitoring ◽

10.1177/14759217211044806 ◽

2021 ◽

pp. 147592172110448

Author(s):

Han Zhang ◽

Jing Lin ◽

Jiadong Hua ◽

Tong Tong

Keyword(s):

Sparse Coding ◽

Lamb Wave ◽

Structural Damage ◽

Damage Identification ◽

Lamb Waves ◽

Damage Localization ◽

Coding Method ◽

Data Driven Approach ◽

Band Pass ◽

Thresholding Algorithm

Lamb wave-based damage identification and localization methods hold the potential for nondestructive evaluation and structural health monitoring. Dispersive and multimodal characteristics lead to complicated Lamb wave signals that are challenging to be analyzed. Deep learning architectures could identify damage-related features effectively. Convolutional neural network (CNN) is a promising architecture that has been widely applied in recent years. However, this data-driven approach still lacks a certain degree of physical interpretability and requires a large number of parameters. In this article, an interpretable Lamb wave convolutional sparse coding (LW-CSC) method is proposed for structural damage identification and localization. First, toneburst signals at different center frequencies are considered in the first convolutional layer. The network convolves the waveforms with a set of parametrized functions that implement band-pass filters, which performs more physical interpretability compared to conventional CNN model. Subsequently, the damage features are extracted according to the multi-layer iterative soft thresholding algorithm for multi-layer CSC model, which could realize a deeper network without adding parameters unlike CNN. Finally, Lamb wave-based damage localization is visualized using an imaging algorithm. The experimental results demonstrate that the proposed method not only enables improvement of the classification accuracy but also achieves structural damage localization accurately.

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