Localization of Barely Visible Impact Damage (BVID) in Composite Plates

2014 ◽  
Vol 627 ◽  
pp. 217-220 ◽  
Author(s):  
Shi Yang Meng ◽  
Zahra Sharif Khodaei ◽  
M.H. Aliabadi
Keyword(s):  
Damage Detection ◽  
Impact Damage ◽  
Composite Plates ◽  
Structural Features ◽  
Detection Technique ◽  
Stiffened Panel ◽  
Imaging Method ◽  
Flat Panel ◽  
Isotropic Composite ◽  
The Impact

This paper exploits the implementation of a delay-and-sum imaging method using Lamb wave signals to localise barely visible impact damage (BVID) in quasi-isotropic composite panels. The structural discontinuities, such as opening and stiffener, has also been tested to reflect the common structural features of an aircraft and to examine the feasibility of the proposed detection technique. The prediction results are compared with ultrasonic C-scan images, which indicate location error for three different panels –flat panel, flat panel with an opening and stiffened panel. The accuracy is believed to be improved by increasing the number of transducers. Overall the proposed damage detection technique, with the use of only four transducers, demonstrated sufficient accuracy and efficiency in impact damage detection and can be applied alongside the traditional NDT inspections for providing a priori information of the impact damage location.

Experimental Investigation on Improving Electromechanical Impedance Based Damage Detection by Temperature Compensation

2013 ◽  
Vol 569-570 ◽  
pp. 1132-1139 ◽  
Author(s):  
Thomas Siebel ◽  
Mihail Lilov
Keyword(s):  
Damage Detection ◽  
Structural Damage ◽  
Temperature Compensation ◽  
Impact Damage ◽  
Correlation Coefficients ◽  
Electromechanical Impedance ◽  
Reinforced Plastic ◽  
Influence Of Temperature On ◽  
Compensation Approach ◽  
The Impact

The sensitivity of the electromechanical impedance to structural damage under varying temperature is investigated in this paper. An approach based on maximizing cross-correlation coefficients is used to compensate temperature effects. The experiments are carried out on an air plane conform carbon fiber reinforced plastic (CFRP) panel (500mm x 500mm x 5mm) instrumented with 26 piezoelectric transducers of two different sizes. In a first step, the panel is stepwise subjected to temperatures between-50 °C and 100 °C. The influence of varying temperatures on the measured impedances and the capability of the temperature compensation approach are analyzed. Next, the sensitivity to a 200 J impact damage is analyzed and it is set in relation to the influence of a temperature change. It becomes apparent the impact of the transducer size and location on the quality of the damage detection. The results further indicate a significant influence of temperature on the measured spectra. However, applying the temperature compensation algorithm can reduce the temperature effect at the same time increasing the transducer sensitivity within its measuring area. The paper concludes with a discussion about the trade-off between the sensing area, where damage should be detected, and the temperature range, in which damage within this area can reliably be detected.

Detection of Impact Location for Composite Stiffened Panel Using FBG Sensors

2010 ◽  
Vol 123-125 ◽  
pp. 895-898 ◽  
Author(s):  
Sang Oh Park ◽  
Byeong Wook Jang ◽  
Yeon Gwan Lee ◽  
Yoon Young Kim ◽  
Chun Gon Kim ◽  
...  
Keyword(s):  
Signal Processing ◽  
Noise Level ◽  
Composite Plate ◽  
Composite Plates ◽  
Stiffened Panel ◽  
Arrival Times ◽  
Fbg Sensor ◽  
Composite Stiffened Panel ◽  
Fbg Sensors ◽  
The Impact

We carried out experiments to detect impact locations on a composite plate using two types of composite plates, a composite flat plate with a constant thickness of 5 mm and a composite stiffened panel with stringers. Four multiplexed FBG sensors were attached to the bottom surface of the composite plates to acquire impact signals. The FBG sensor wavelength shift data were collected at a sampling frequency of 40 kHz using a high-speed FBG interrogator (SFI-710, Fiberpro Inc., Korea). The arrival times of the impact signals at each FBG sensor were obtained using a signal processing procedure. The arrival times were affected by noise level and signal-to-noise ratio. In order to overcome this weakness, signal processing techniques such as wavelet decomposition, normalization using each noise level and filtering with a moving average were adopted. To calculate the impact locations of the composite plate, a neural network algorithm was applied.

Assessing the Scaling Subtraction Method for Impact Damage Detection in Composite Plates

2017 ◽  
Vol 36 (2) ◽  
Author(s):  
Maria Cristina Porcu ◽  
Lukasz Pieczonka ◽  
Andrea Frau ◽  
Wieslaw Jerzy Staszewski ◽  
Francesco Aymerich
Keyword(s):  
Damage Detection ◽  
Impact Damage ◽  
Composite Plates ◽  
Subtraction Method

scholarly journals Enhanced Impact-Resistance of Aeronautical Quasi-Isotropic Composite Plates Through Diffused Water Molecules in Epoxy

2020 ◽  
Author(s):  
Furqan Ahmad ◽  
Fethi Abbassi ◽  
Mazhar Ul-Islam ◽  
Frédéric JACQUEMIN ◽  
Jung-Wuk Hong
Keyword(s):  
Carbon Fiber ◽  
Impact Resistance ◽  
Composite Plates ◽  
Hot Water ◽  
Low Velocity Impact ◽  
Low Velocity ◽  
Segmental Mobility ◽  
Impact Tests ◽  
Isotropic Composite ◽  
The Impact

Abstract In order to elucidate the hygroscopic effects on impact-resistance of carbon fiber/epoxy quasi-isotropic composite plates, low-velocity impact tests are conducted on dry and hygroscopically conditioned plates, respectively, under identical configurations. For the impact tests, plates were immersed in the hot water at 80 °C to absorb a different amount of moisture content (MC). Experimental results reveal that the presence of the MC plays a pivotal role by improving the impact-resistance of composite plates. Plates with higher percentage of MC could behave elastically to a larger strain, yielding larger deflection under impact loading. From SEM fractographies, it is observed that small disbanding grows at the interface of epoxy and carbon fiber due to absorbed MC. After absorbing MC, most of impact enegy is dissipated in hygroscopic conditioned composite plates throught elastic deformation and overall less damage is induced in wet composite plates compare to the dry plate. We can postulate that the presence of MC increases the elastic limit as well as ductility of the epoxy by promoting chain segmental mobility of the polymer molecules, which eventually leads to the enhancement of the impact-resistance of wet quasi-isotropic composite plates in comparison with the dry plate.

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. 

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 Acoustic Emission Localization in a Composite Stiffened Panel Using a Time Reversal Algorithm

2011 ◽  
Vol 471-472 ◽  
pp. 910-915
Author(s):  
Francesco Ciampa ◽  
Michele Meo
Keyword(s):  
Acoustic Emission ◽  
Time Reversal ◽  
Mode Conversion ◽  
Research Work ◽  
Composite Panel ◽  
Computational Time ◽  
Stiffened Panel ◽  
Imaging Method ◽  
Impact Point ◽  
The Impact

This research work presents an in-situ imaging method for the localization of the impact point in complex anisotropic structures with diffuse field conditions, using only one passive transducer. The proposed technique is based on the time reversal approach applied to a number of waveforms stored into a database containing the experimental Green’s function of the medium. The present method exploits the benefits of multiple scattering, mode conversion and boundaries reflections to achieve the focusing of the source with high resolution. The optimal re-focusing of the back propagated wave field at the impact point is accomplished through a “virtual” imaging process, which does not require any iterative algorithms and a priori knowledge of the mechanical properties of the structure. The robustness of the time reversal method is experimentally demonstrated on a stiffened composite panel and the source position can be retrieved with a high level of accuracy (error less than 3%). The simple configuration, minimal processing requirements and computational time (less than 1 sec) make this method a valid alternative to the conventional imaging structural health monitoring systems for the acoustic emission source localization.

Impact Damage Monitoring in Composite Plates

2004 ◽  
Author(s):  
Frank J. Shih ◽  
Sauvik Banerjee ◽  
Ajit K. Mal
Keyword(s):  
Impact Load ◽  
Impact Damage ◽  
Composite Plates ◽  
Impact Testing ◽  
Far Field ◽  
Internal Damage ◽  
Distributed Sensors ◽  
Surface Motion ◽  
Impact Monitoring ◽  
The Impact

This paper is concerned with the real-time detection of internal damage in composite structural components during impact using the far-field surface motion generated by these events. Impact tests are carried out on graphite epoxy composite plates using an instrumented impact testing system. Contact force and surface motion are measured at several locations on the plate surface. The far-field surface motions, both flexural and extensional waves in the composite plate, are modeled using both approximate and exact solution methods. Postimpact test were performed to determine the extent of internal damage caused by the impact load. Further research on the detection method can lead to the development of a viable impact monitoring system for composite aerospace structures using distributed sensors.

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