scholarly journals 3D Modelling of the Scattering of the Fundamental Anti-Symmetric Lamb Mode (A0) Propagating within a Point-Impacted Transverse-Isotropic Composite Plate

2021 ◽  
Vol 11 (16) ◽  
pp. 7276
Author(s):  
Dilbag Singh ◽  
Mourad Bentahar ◽  
Charfeddine Mechri ◽  
Rachid El Guerjouma
Keyword(s):  
Composite Plate ◽  
Impact Damage ◽  
Elastic Stiffness ◽  
Wave Mode ◽  
Guided Wave ◽  
Domain Model ◽  
Isotropic Composite ◽  
Damaged Zone ◽  
The Impact ◽  
Lamb Mode

The present paper deals with an effort to model impact damage in 3D-FE simulation. In this work, we studied the scattering behavior of an incident A0 guided wave mode propagating towards an impacted damaged zone created within a quasi-isotropic composite plate. Besides, barely visible impact damage of the desired energy was created and imaged using ultrasonic bulk waves in order to measure the size of the damage. The 3D-FE frequency domain model is then used to simulate the scattering of an incident guided wave at a frequency below an A1 cut-off with a wavelength comparable to the size of the damaged zone. The damage inside the plate is modeled as a conical-shaped geometry with decayed elastic stiffness properties. The model was first validated by comparing the directivity of the scattered fields for the A0 Lamb mode predicted numerically with the experimental measurements. The modeling of the impact zone with conical-shape geometry showed that the scattering directivity of the displacement field depends significantly on the size (depth and width) of the conical damage created during the point-impact of the composite with potential applications allowing the determination of the geometric characteristics of the impacted areas.

scholarly journals Multimode Guided Wave Detection for Various Composite Damage Types

2020 ◽  
Vol 10 (2) ◽  
pp. 484 ◽  
Author(s):  
Hanfei Mei ◽  
Robin James ◽  
Mohammad Faisal Haider ◽  
Victor Giurgiutiu
Keyword(s):  
Composite Plate ◽  
Guided Waves ◽  
Impact Damage ◽  
Guided Wave ◽  
Wave Detection ◽  
Composite Damage ◽  
Cfrp Composite ◽  
The Impact ◽  
Damage Types ◽  
Wave Modes

This paper presents a new methodology for detecting various types of composite damage, such as delamination and impact damage, through the application of multimode guided waves. The basic idea is that various wave modes have different interactions with various types of composite damage. Using this method, selective excitations of pure-mode guided waves were achieved using adjustable angle beam transducers (ABTs). The tuning angles of various wave modes were calculated using Snell’s law applied to the theoretical dispersion curves of composite plates. Pitch–catch experiments were conducted on a 2-mm quasi-isotropic carbon fiber-reinforced polymer (CFRP) composite plate to validate the excitations of pure fundamental symmetric mode (S0) and shear horizontal mode (SH0). The generated pure S0 mode and SH0 mode were used to detect and separate the simulated delamination and actual impact damage. It was observed that S0 mode was only sensitive to the impact damage, while SH0 mode was sensitive to both simulated delamination and impact damage. The use of pure S0 and SH0 modes allowed for damage separation. In addition, the proposed method was applied to a 3-mm-thick quasi-isotropic CFRP composite plate using multimode guided wave detection to distinguish between delamination and impact damage. The experimental results demonstrated that the proposed method has a good capability to detect and separate various damage types in composite structures.

scholarly journals Assessment of low-velocity impact damage in composites by the measure of second-harmonic guided waves with the phase-reversal approach

2019 ◽  
Vol 103 (1) ◽  
pp. 003685041988107 ◽  
Author(s):  
Weibin Li ◽  
Chang Jiang ◽  
Xinlin Qing ◽  
Liangbing Liu ◽  
Mingxi Deng
Keyword(s):  
Guided Waves ◽  
Second Harmonic ◽  
Impact Damage ◽  
Guided Wave ◽  
Second Order ◽  
Low Velocity Impact ◽  
Low Velocity ◽  
Velocity Impact ◽  
Phase Reversal ◽  
The Impact

Structural strength and integrity of composites can be considerably affected by the low-velocity impact damage due to the unique characteristics of composites, such as layering bonded by adhesive and the weakness to impact. For such damage, there is an urgent need to develop advanced nondestructive testing approaches. Despite the fact that the second harmonics could provide information sensitive to the structural health condition, the diminutive amplitude of the measured second-order harmonic guided wave still limits the applications of the second-harmonic generation–based nonlinear guided wave approach. Herein, laminated composites suffered from low-velocity impact are characterized by use of nonlinear guided waves. An enhancement in the signal-to-noise ratio for the measure of second harmonics is achieved by a phase-reversal method. Results obtained indicate a monotonic correlation between the impact-induced damage in composites and the relative acoustic nonlinear indicator of guided waves. The experimental finding in this study shows that the measure of second-order harmonic guided waves with a phase-reversal method can be a promising indicator to impact damage rendering in an improved and reliable manner.

scholarly journals Modeling Analysis of Guided Ultrasonic Waves in Composite Plates with Impact Damage

2018 ◽  
Vol 7 (4.26) ◽  
pp. 175
Author(s):  
Noorfaten Asyikin Ibrahim ◽  
Bibi Intan Suraya Murat
Keyword(s):  
Composite Structures ◽  
Impact Damage ◽  
Composite Plates ◽  
Guided Wave ◽  
Ultrasonic Waves ◽  
Fe Model ◽  
Element Analysis ◽  
Damage Area ◽  
Guided Ultrasonic Waves ◽  
The Impact

This paper investigates the propagation of guided ultrasonic waves and the interaction with impact damage in composite plates using a full three-dimensional Finite Element analysis. Impact damage in the composite plate was modeled as rectangular- and T-shaped delaminations. In order to provide guidelines for extending the modeling of realistic multimode impact damage, the impact damage was modeled as a combination of the delamination and reduced materials properties. The information obtained from these methods was compared to the experimental results around the damage area for a validation. There was a reasonable similarity between the experimental and FE results. The FE simulations can effectively model the scattering characteristics of the A0 mode wave propagation in anisotropic composite plates. This suggests that the simplified and easy-to-implement FE model could be used to represent the complex impact damage in composite plates. This could be useful for the improvement of the FE modeling and performance of guided wave methods for the in-situ NDE of large composite structures. 

Experimental Model of Impact Damage for Guided Wave-Based Inspection of Composites

2018 ◽  
Vol 1 (4) ◽  
Author(s):  
Mohammad H. Sherafat ◽  
Nicolas Quaegebeur ◽  
Pascal Hubert ◽  
Larry Lessard ◽  
Patrice Masson
Keyword(s):  
Experimental Model ◽  
Composite Structures ◽  
Impact Damage ◽  
Incident Angle ◽  
Energy Levels ◽  
Laser Doppler Vibrometer ◽  
Design Guidelines ◽  
Guided Wave ◽  
Antisymmetric Mode ◽  
The Impact

The objective of this work is to assess to which extent the interaction of antisymmetric ultrasonic guided waves with impact damage can be captured with an experimental model consisting of a single artificial delamination in composite structures. The structures of interest are composed of unidirectional prepreg carbon fiber-reinforced polymer (CFRP) with a quasi-isotropic layup. The artificial delamination is introduced into the laminate using two circular Teflon tapes during manufacturing and the realistic damage is simulated by impacting the samples at two energy levels. Two colocalized rectangular piezoceramics are used to generate an antisymmetric mode and noncontact measurement is performed using a three-dimensional (3D) laser Doppler vibrometer (3D-LDV) to extract the required information for evaluation of the reflection, transmission, as well as the scattering behavior of the antisymmetric mode. The corresponding coefficients as a function of frequency, incident angle, and type of damage are extracted. It is found that the amplitude of the coefficients and directivity patterns of scattered waves are barely affected by incident angle but significantly by the impact energy. In light of the results, design guidelines are proposed for efficient guided wave inspection of composite structures submitted to impacts.

Guided Wave Generation and Propagation in Self-Sensing Piezoelectric Composite Plates for Structural Health Monitoring

2018 ◽  
Author(s):  
Junzhen Wang ◽  
Yanfeng Shen
Keyword(s):  
Finite Element ◽  
Impact Damage ◽  
Composite Plates ◽  
Wave Generation ◽  
Absorbing Boundary Conditions ◽  
Guided Wave ◽  
Piezoelectric Composite ◽  
Finite Element Software ◽  
The Impact ◽  
Wave Modes

This paper presents a systematic numerical investigation of guided wave generation, propagation, interaction with damage, and reception in anisotropic piezoelectric composite plates. This approach employs piezoelectric composite materials as both load bearing and sensing elements. Finite element modal analysis of a plate unit cell with Bloch-Floquet boundary condition is performed to understand the guided wave propagation characteristics in piezoelectric composite plates. The guided wave generation and tuning characteristics are investigated using the harmonic analysis model with absorbing boundary conditions. The relationship between the generated wave modes and the laminate layup orientations is studied. Subsequently, an impact damage is introduced and modeled as a group of cone shape delaminated layers and stiffness losses within the layers through the thickness direction. 2D and 3D transient dynamic coupled-field finite element models are constructed to simulate the procedure of guided wave generation, propagation, interaction with the impact damage, and reception in an orthotropic piezoelectric composite plate using the commercial finite element software (ANSYS). In addition, Contact Acoustic Nonlinearity (CAN) is simulated via time domain transient analysis. Advanced signal processing techniques are used to extract the distinctive nonlinear features. The frequency-wavenumber analysis is further adopted to decipher wave modes and frequency components in the scattered wave field. This paper finishes with concluding remarks and suggestions for future work.

Barely visible impact damage imaging using non-contact air-coupled transducer/laser Doppler vibrometer system

2016 ◽  
Vol 16 (6) ◽  
pp. 663-673 ◽  
Author(s):  
MS Harb ◽  
FG Yuan
Keyword(s):  
Cross Correlation ◽  
Impact Damage ◽  
Laser Doppler Vibrometer ◽  
Wave Mode ◽  
Guided Wave ◽  
Fiber Reinforced Polymer ◽  
Carbon Fiber Reinforced Polymer ◽  
Imaging Condition ◽  
Reinforced Polymer ◽  
Impact Damages

The aim of this study is to investigate the capability of the zero-lag cross-correlation imaging condition of an A0 Lamb wave mode in imaging a barely visible impact damage in a carbon fiber–reinforced polymer composite using a fully non-contact-guided wave-based non-destructive inspection system. A 16-ply (45/0/-45/90)2s carbon fiber–reinforced polymer laminate was impacted at three different locations with different impact energies using a drop ball at three drop heights causing three barely visible impact damages with different sizes. The A0 Lamb wave mode is generated inside the laminate using a circular air-coupled transducer and detected along the damaged region using a laser Doppler vibrometer. The measured wavefield is then decomposed into a forward and backward propagating wavefields by applying a frequency–wavenumber filtering post-processing technique. The decomposed wavefields are then cross-correlated in the frequency domain using zero-lag cross-correlation imaging condition producing a detailed cumulative damage image. The images obtained in frequency domain highlight the three damaged areas with higher zero-lag cross-correlation values compared to other parts of the inspected areas. The experimental investigation has shown a good correlation between the zero-lag cross-correlation imaging condition and C-scan images, which demonstrate a strong capability of guided wave zero-lag cross-correlation imaging condition technique in approximating the location and size of relatively small barely visible impact damages in thin composite structures.

scholarly journals Simulation of Quasi-Isotropic E-Glass Composite Laminate at Low Velocity Impact with Cohesive Interface Elements

2020 ◽  
pp. 128-140
Keyword(s):  
Composite Laminate ◽  
Impact Test ◽  
Impact Damage ◽  
Low Velocity Impact ◽  
Low Velocity ◽  
Interface Elements ◽  
Cohesive Interface ◽  
Isotropic Composite ◽  
Structural Impact ◽  
The Impact

This paper examines the expediency of interface elements in modeling of impact damage analysis for Eglass composite laminate under low velocity impact test. Numerical modelsare built adopting cohesive interface behavior to authenticate the cross-ply damage response; and successively used the strategy to model the impact response of quasi-isotropic composite laminate. Impact test are performed to characterize the induced-damage behavior in quasi-isotropic composite laminate at different impact energy test in terms of impact force, displacement and damage size as well as the stress failure trajectory. Numerical result shows reliability of the model for structural impact analysisin damage initiation and progression in laminated composite plates. The simulation result though reveals large deformation, yet, did not yield in total fracture. This development shows the importance of adopting interface elements in structural impact damage criterion to trigger constraints effect on initiation phase.The study also reveals that the bottom most surface suffers huge deformation compare to the impact surface. It divulges that the extent of damage area in each ply of the composite laminate orients in the fiber direction in ‘star-shaped contour. The main novelty is the capability of using this model for structural impact analysis on both cross-ply and quasi-isotropic composite laminate.

scholarly journals Study of modal acoustic emission to monitor the impact damage in a composite plate

2017 ◽  
Vol 19 (5) ◽  
pp. 3335-3348 ◽  
Author(s):  
Baochun Xu ◽  
Jingqiu Wu ◽  
Mulan Wang
Keyword(s):  
Acoustic Emission ◽  
Composite Plate ◽  
Impact Damage ◽  
The Impact

Modelling Anisotropy Influence on Guided Wave Scattering at Composite Delaminations

2021 ◽  
Author(s):  
Flora Hervin ◽  
Paul Fromme
Keyword(s):  
Composite Laminates ◽  
Guided Waves ◽  
Impact Damage ◽  
Scattered Wave ◽  
Unidirectional Composite ◽  
Guided Wave ◽  
Parameter Study ◽  
Laser Vibrometer ◽  
Composite Panels ◽  
Isotropic Composite

Abstract Carbon fibre reinforced composite laminates are widely used in aerospace structures but are prone to barely visible impact damage (BVID). Depending on impact severity, delaminations can form below the surface of the laminate, reducing the load bearing capacity. Efficient structural health monitoring (SHM) of composite panels can be achieved using guided waves propagating along the structure. Propagation and scattering of the A0 Lamb wave mode in a quasi-isotropic composite laminate was modelled using full three-dimensional (3D) Finite Element (FE) simulations. Individual ply layers were modelled using homogeneous unidirectional composite material properties to accurately capture the anisotropy effects. FE predictions for scattering and energy trapping at delaminations were compared to experimental measurements. Noncontact, full-wavefield guided wave measurements were obtained using a laser vibrometer. Good agreement was found between experiments and FE predictions. The effect of delamination shape and depth was investigated through a numerical parameter study. The angular dependency of the amplitude of the scattered wave was calculated. The influence of ply layer anisotropy on wave propagation in an undamaged laminate was investigated numerically. The sensitivity of guided waves for the detection of delaminations due to barely visible impact damage (BVID) in composite panels has been verified.

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