scholarly journals Fast Localization of Impact Damage on Woven CFRP Based on Sparse Microwave Imaging

2020 ◽  
Author(s):  
Ruslee Sutthaweekul ◽  
Gui Yun Tian
Keyword(s):  
Feature Extraction ◽  
Impact Damage ◽  
Principal Component ◽  
Large Area ◽  
Localization Accuracy ◽  
Damage Area ◽  
Reinforced Plastic ◽  
The Impact ◽  
Sampling Sequences ◽  
Impact Damages

Microwave open-ended waveguide scanning has been proved to be a promising NDT technique for imaging of woven carbon fiber reinforced plastic (CFRP) with impact damages. However, it uses a conventional C-scan technique, which is excessively time-consuming and therefore it is not practical for defect detection in a large area. Moreover, without proper feature extraction, the appearance of woven texture within the impact damage area opposes to the localization of the impact. This work proposes a novel framework for fast impact damage localization by means of discrete sparse measurement. Also, the localization accuracy of sparse measurement is improved by mitigating effect of woven texture using principal component analysis (PCA) for feature extraction. The performance of the proposed methods is evaluated by sets of incremental measurements. The performance of the proposed system is and evaluated by localizing the impact damage of 100 non-uniform sparse sampling sequences. Results show that our proposed technique can accurately localize the impact damage with number of samples less than 10% of full measurements, giving approximately 10 times faster than that of the conventional C-scan.

scholarly journals Impact Damages Detection on CFRP Using Eddy Current Pulsed Thermography

2020 ◽  
Author(s):  
Abdoulaye Ba ◽  
Qiuji Yi ◽  
Junzhen Zhu ◽  
Huu-Kien Bui ◽  
Gui Yun Tian ◽  
...  
Keyword(s):  
Eddy Current ◽  
Pulse Compression ◽  
Impact Damage ◽  
Flaw Detection ◽  
Principal Component ◽  
Destructive Testing ◽  
Test Configuration ◽  
Damage Area ◽  
Technique Optimization ◽  
Impact Damages

Carbon Fiber Reinforced Polymer (CFRP) materials are widely used in aerospace due to their low weigh to strength ratio. Non-destructive Testing (NDT) Techniques becomes a necessity with increasing use of CFRP materials. Induction Thermography is a new NDT technique that can be exploited as a promising fast and global control. However, the detection of typical flaws in carbon composites such as delamination, fibers rupture and impact damages need to be further investigated in order to optimize the technique. Optimization can be done in the test configuration level and by the use an appropriate image technique. In this paper Eddy Current Pulse Compression Thermography (ECPuCT) is used to detect impact damages on CFRP materials. The Principal Component Analysis (PCA) based image processing technique is used to detect and visualize impact damage area from transient thermal images. Flaw detection results using experimental measures will be shown and discussed.

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.

scholarly journals Impact Damage Resistance and Post-Impact Tolerance of Optimum Banana-Pseudo-Stem-Fiber-Reinforced Epoxy Sandwich Structures

2020 ◽  
Vol 10 (2) ◽  
pp. 684 ◽  
Author(s):  
Mohamad Zaki Hassan ◽  
S. M. Sapuan ◽  
Zainudin A. Rasid ◽  
Ariff Farhan Mohd Nor ◽  
Rozzeta Dolah ◽  
...  
Keyword(s):  
Composite Structures ◽  
Sandwich Structures ◽  
Impact Damage ◽  
Fiber Composite ◽  
Peak Load ◽  
Weight Ratio ◽  
Synthetic Fiber ◽  
Damage Area ◽  
Banana Fibers ◽  
The Impact

Banana fiber has a high potential for use in fiber composite structures due to its promise as a polymer reinforcement. However, it has poor bonding characteristics with the matrixes due to hydrophobic–hydrophilic incompatibility, inconsistency in blending weight ratio, and fiber length instability. In this study, the optimal conditions for a banana/epoxy composite as determined previously were used to fabricate a sandwich structure where carbon/Kevlar twill plies acted as the skins. The structure was evaluated based on two experimental tests: low-velocity impact and compression after impact (CAI) tests. Here, the synthetic fiber including Kevlar, carbon, and glass sandwich structures were also tested for comparison purposes. In general, the results showed a low peak load and larger damage area in the optimal banana/epoxy structures. The impact damage area, as characterized by the dye penetration, increased with increasing impact energy. The optimal banana composite and synthetic fiber systems were proven to offer a similar residual strength and normalized strength when higher impact energies were applied. Delamination and fracture behavior were dominant in the optimal banana structures subjected to CAI testing. Finally, optimization of the compounding parameters of the optimal banana fibers improved the impact and CAI properties of the structure, making them comparable to those of synthetic sandwich composites.

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 Impact Resistance of Plain and Twill Fabric in GFRP Measured by Active Thermography

2018 ◽  
Vol 27 (5) ◽  
pp. 096369351802700 ◽  
Author(s):  
G. Strugala ◽  
M. Landowski ◽  
M. Zaremba ◽  
J. Turowski ◽  
M. Szkodo
Keyword(s):  
Impact Energy ◽  
Impact Damage ◽  
Impact Resistance ◽  
Damage Area ◽  
Plain Weave ◽  
Active Thermography ◽  
Glass Fibre Reinforced Polymer ◽  
Glass Fibre Reinforced ◽  
The Impact ◽  
Twill Weave

This paper discusses the impact resistance of glass-fibre reinforced polymer (GFRP) composites depending on the type of reinforcement – plain or twill weave. The values of impact energy were: 3J, 10J and 15J. Specimens featuring twill weave transferred higher force during the impact as compared with plain weave specimens. It was observed that an increase of impact energy was accompanied by an increase of the disproportion in transferred forces, in favour of twill weave specimens. Impact damage (in both types of weave) occurring as a result of 3J impact was undetectable with active thermography method. The damage area measured by means of active thermography for impact energy values equal to 10J and 15J proved that the type of reinforcement significantly influences the impact resistance of a composite. This has been justified by smaller damage areas with high spot intensity of damage in plain weave specimens and highly dispersed damage with lower intensity in twill weave specimens.

Impact Damage Behavior of Composite Stiffened Plates

2011 ◽  
Vol 117-119 ◽  
pp. 954-957
Author(s):  
Li Yan ◽  
Xue Feng An ◽  
Chen Qian Zhang ◽  
Xiao Su Yi
Keyword(s):  
Impact Damage ◽  
Visual Observation ◽  
Impact Testing ◽  
Low Velocity Impact ◽  
Stiffened Plates ◽  
Low Velocity ◽  
Damage Behavior ◽  
Damage Area ◽  
Impact Position ◽  
The Impact

Damage behavior of composite stiffened plates of structure I and structure II at different positions and under different impact energy subjected to low-velocity impact testing was studied in this paper. Visual observation and ultrasonic C-scanning were also employed to inspect the damage size. The results showed that damage behavior of composite stiffened plates was not only related to damage behavior of laminates, but also related to damage between stringer and laminate and damage of stringer itself. It was found that the mechanism of absorbing energy varies with the impact position, as well as the damage behavior. When the impact position was near stringer, partial energy was absorbed by stringer to make stringer and laminate disengage and damage area of laminates was smaller. Damage behavior of composite stiffened plates varies with the structure. Damage area of samples of structure II was smaller than that of samples of structure I. It was estimated preliminarily that design of structure II was better than that of structure I.

Damage Classification in CFRP Laminates Using Principal Component Analysis (PCA) Approach

2012 ◽  
Vol 225 ◽  
pp. 189-194
Author(s):  
Mohamed Thariq Hameed Sultan ◽  
Azmin Shakrine M. Rafie ◽  
Noorfaizal Yidris ◽  
Faizal Mustapha ◽  
Dayang Laila Majid
Keyword(s):  
Signal Processing ◽  
Damage Detection ◽  
Impact Damage ◽  
Research Work ◽  
Principal Component ◽  
Damage Classification ◽  
Cfrp Laminates ◽  
Work Related ◽  
Detection And Identification ◽  
The Impact

Signal processing is an important element used for identifying damage in any SHM-related application. The method here is used to extract features from the use of different types of sensors, of which there are many. The responses from the sensors are also interpreted to classify the location and severity of the damage. This paper describes the signal processing approaches used for detecting the impact locations and monitoring the responses of impact damage. Further explanations are also given on the most widely-used software tools for damage detection and identification implemented throughout this research work. A brief introduction to these signal processing tools, together with some previous work related to impact damage detection, are presented and discussed in this paper.

scholarly journals Influence of Projectile Nose Shape on Ballistic Limit and Damage to Glass/Vinyl Ester Composite Plates

2011 ◽  
Vol 20 (5) ◽  
pp. 096369351102000
Author(s):  
M. Sasikumar ◽  
V. Sundareswaran
Keyword(s):  
Vinyl Ester ◽  
Composite Plates ◽  
Ballistic Limit ◽  
Fibre Glass ◽  
Damage Area ◽  
Frp Composites ◽  
Reinforced Plastic ◽  
Nose Shape ◽  
Ballistic Limit Velocity ◽  
The Impact

In the recent past, the substantial structural strength, light weight and stiffness properties of polymer based composite materials find its application in aircraft and automotive structures at prodigious rate. Fibre glass Reinforced Plastic (FRP) composites are partially elastic and brittle. The present study evaluates the ballistic limit, energy absorbed and the damage area caused by different projectile nose shapes on the composite plates made of glass fibre and vinyl ester resin with the orientation of (0/90)s. The number of plies in the plates is varied to 4, 6 and 8 and thus lead to different thicknesses. The projectile nose geometry is varied (hemispherical, conical, truncated conical, ogival and truncated ogival) to have realistic effect on the impact. The influence of projectile nose shape over ballistic limit is found experimentally and compared with the analytical predictions by H. M. Wen [ 5 , 6 ]. The ballistic limit, perforation mechanism, energy absorption at ballistic limit and the damage area at ballistic limit velocity has been studied. The influence of thickness of the composite plate over the ballistic limit have also been discussed. It is found that the truncated conical nose shaped projectile resulted in highest ballistic limit and largest damage area dominated by delamination. Experimental results showed that the analytical method [ 5 , 6 ] could satisfactorily predict the ballistic limit.

Dent depth visibility versus delamination damage for impact of composite panels by tips of varying radius

2018 ◽  
Vol 52 (19) ◽  
pp. 2691-2705 ◽  
Author(s):  
Mac P Delaney ◽  
Sarah YK Fung ◽  
Hyonny Kim
Keyword(s):  
Composite Laminates ◽  
Impact Damage ◽  
Visual Observation ◽  
Small Radius ◽  
Large Area ◽  
Low Velocity ◽  
Internal Damage ◽  
Damage Level ◽  
Visual Evidence ◽  
The Impact

The ability to visually detect damage from impact events is a common concern for carbon/epoxy composite laminates, particularly because composite materials can sustain impact damage in forms such as delamination and backside fiber breakage that is not directly visible at the site of the impact. Therefore, a relationship drawn between the internal damage level and visibility of surface dents would be useful. An experimental investigation is presented on the relationship between visual detectability and the extent of internal damage created by low-velocity impacts. The specimens examined were 8, 16, and 24 ply carbon/epoxy panels impacted by tips of radii: 12.7, 25.4, 50.8, and 76.2 mm. In order to quantitatively describe the visibility of the damage, the depth and span of the surface dents were considered. The results indicate that there are direct relationships between visible and internal damage, but that these relationships are strongly dependent on the radius of the impact tip. Small radius impactors can leave significant visual evidence (i.e. surface dent) without creating internal damage, while the larger radius blunt impactors can create large-area internal delamination without leaving any visual evidence. Therefore, the visual detectability of impact damage is highly dependent upon tip radius, and the level of internal damage cannot be determined based on visual observation alone, especially since in practice, the radius of an impacting object is not always known.

scholarly journals Study on the Thermal and Impact Resistance Properties of Micro PA66/PU Synergistically Reinforced Multi-Layered Biaxial Weft Knitted Fabric Composites

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Yexiong Qi ◽  
Waqar Iqbal ◽  
Runze Shao ◽  
Yanjin Shi
Keyword(s):  
Impact Damage ◽  
Thermo Gravimetric Analysis ◽  
Impact Resistance ◽  
Mechanical Analysis ◽  
Gravimetric Analysis ◽  
Damage Area ◽  
Comprehensive Properties ◽  
Weft Knitted Fabric ◽  
Failure Morphology ◽  
The Impact

Abstract In this paper, the influence of micro PA66/PU in multi-layered biaxial weft knitted (MBWK) fabric reinforced composites on thermal and impact resistance was studied. The main objective was to investigate the role of micro PA66/PU in terms of improving material performance. The results showed that the addition of micro PA66/PU improved the thermal stability of the MBWK composite. It is observed that the onset degradation temperatures increased by 1.6°C in thermo-gravimetric analysis (TGA) test and the Tg increased by 2.8°C in the dynamic mechanical analysis (DMA) test. Besides, the impact energy absorption of composites increased by 5.3% after the addition of micro PA66/PU. The addition of micro PA66/PU effectively reduced the impact damage area from the failure morphology after impact. In simple words, the addition of micro PA66/PU effectively improves the comprehensive properties of composites.

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