scholarly journals Characterisation of Impact Damage of Composite Structures Using Wavelet-Based Fusion of Ultrasonic and Optical Images

2014 ◽  
Vol 23 (5) ◽  
pp. 096369351402300
Author(s):  
Andrzej Katunin ◽  
Pawel Kostka
Keyword(s):  
Composite Structures ◽  
Damage Identification ◽  
Impact Damage ◽  
Human Perception ◽  
Laminated Plates ◽  
Low Velocity ◽  
Fusion Algorithm ◽  
Fibre Failure ◽  
Optical Images ◽  
The Impact

This paper presents the novel approach for the impact damage characterisation of composite structures, which is based on fusion of ultrasonic scans and optical images. Both internal (inter-fibre failure, fibre failure, delaminations) and external (scratches and surface cracks) damages occurred in the composite structures during their operation need to be analysed due to their occurrence on both of these levels, especially in the case of impact damages. The presented approach allows for the improvement of the characterisation quality, i.e. the whole damaged area could be detected and localized. In order to assure the proper damage identification the wavelet-based fusion with application of appropriate wavelets and parameters of a fusion algorithm was used, which allows for distinction of different types of damages and overall improvement of the resulted image with respect to the human perception capability. The approach was validated experimentally on the glass-epoxy laminated plates after the low-velocity impacts. Representative cases of damaged structure were presented and analysed.

An Enhanced Time-Reversal Method for Impact Damage Monitoring on Plate-Like Structures

2012 ◽  
Vol 525-526 ◽  
pp. 365-368
Author(s):  
Chun Lin Chen ◽  
Yu Long Li ◽  
Fuh Gwo Yuan
Keyword(s):  
Time Reversal ◽  
Composite Structures ◽  
Impact Damage ◽  
High Energy ◽  
Low Velocity ◽  
Energy Impact ◽  
Location Detection ◽  
Focusing Property ◽  
The Impact ◽  
Impact Events

Based on the self-focusing property of time-reversal (T-R) concept, a time focusing parameter was suggested to improve the impact source identification method developed in authors previous work. This paper presents a further study on monitoring relatively high energy impact events which caused induced damage on structures. Numerical verifications for a finite isotropic plate and a composite plate under low velocity impacts are performed to demonstrate the versatility of T-R method for impact location detection with induced plastic deformation and delamination damage on metallic and composite structures respectively. The focusing property of T-R concept was adequately utilized to detect impact/damage location. The results show that impact events with various features can be localized using T-R method by introducing the time focusing parameter. It is suited to monitor serious impact events on plate like structures in practice in future.

Real-time monitoring of low-velocity impact damage for composite structures with the omnidirection carbon nanotubes’ buckypaper sensors

2018 ◽  
Vol 18 (2) ◽  
pp. 454-465 ◽  
Author(s):  
Shaowei Lu ◽  
Kai Du ◽  
Xiaoqiang Wang ◽  
Caijiao Tian ◽  
Duo Chen ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Composite Structures ◽  
Impact Damage ◽  
Low Velocity Impact ◽  
Sensor Technology ◽  
Gauge Factor ◽  
Low Velocity ◽  
Repeated Impact ◽  
Velocity Impact ◽  
The Impact

A novel, omnidirectional, nanomaterial-based sensor technology which can provide wide area damage detection of composite structures was proposed in this work. The behaviors of the buckypaper sensors subjected to both tensile and low-velocity impact were investigated. The experimental results showed that the rectangle buckypaper sensor has a large range of sensing coefficients from 21.40 to 35.83 at different directions under tensile. However, the circular buckypaper sensor has a steady sensing coefficient of about 155.63. Thus, the circular buckypaper sensor as a kind of omnidirectional sensor was chosen to monitor the impact damage. The low-velocity impact damage of composite structures is characterized by the gauge factor of omnidirectional buckypaper sensors and the results of C-scanning. Omnidirectional buckypaper sensors’ electrical resistance increases with repeated impact loading; composite structure elastic deformation and damage evolution can be identified from resistance change. Experiment results show that structure monitoring based on the omnidirectional buckypaper sensor not only can detect small barely visible impact damage flaws and the damage evaluation of composite structures subjected to impact but also can determine the location of low-velocity impact damage through the analysis of results. Through comparison with C-scan, the results have preliminarily demonstrated that the omnidirectional carbon nanotubes’ buckypaper sensor can serve as an efficient tool for sensing the evolution of impact damage as well as serve structural health monitoring of composite structures.

Kernel Feature Space Based Low Velocity Impact Monitoring

2012 ◽  
Author(s):  
Yingtao Liu ◽  
Masoud Yekani Fard ◽  
Aditi Chattopadhyay
Keyword(s):  
Composite Structures ◽  
Impact Damage ◽  
Damage Index ◽  
Low Velocity Impact ◽  
Kernel Principal Component Analysis ◽  
Monitoring Methods ◽  
Low Velocity ◽  
Velocity Impact ◽  
Statistical Feature ◽  
The Impact

Impact damage has been identified as a critical form of defect that constantly threatens the reliability of composite structures, such as those used in aircrafts and naval vessels. Low energy impacts can introduce barely visible damage and cause structural degradation. Therefore, efficient structural health monitoring methods, which can accurately detect, quantify, and localize impact damage in complex composite structures, are required. In this paper a novel damage detection methodology is demonstrated for monitoring and quantifying the impact damage propagation. Statistical feature matrices, composed of features extracted from the time and frequency domains, are developed. Kernel Principal Component Analysis (KPCA) is used to compress and classify the statistical feature matrices. Compared with traditional PCA algorithm, KPCA method shows better feature clustering and damage quantification capabilities. A new damage index, formulated using Mahalanobis distance, is defined to quantify impact damage. The developed methodology has been validated using low velocity impact experiments with a sandwich composite wing.

The Use of Quasi-Static Indentation Testing to Evaluate Low-Velocity Impact Resistance of Ex Situ Toughened Composite

2014 ◽  
Vol 697 ◽  
pp. 35-40
Author(s):  
Hui Min Dong ◽  
Xue Feng An ◽  
Xiao Su Yi ◽  
Zheng Tao Su
Keyword(s):  
Impact Damage ◽  
Low Velocity Impact ◽  
Ex Situ ◽  
Indentation Testing ◽  
Low Velocity ◽  
Static Tests ◽  
Velocity Impact ◽  
Fibre Failure ◽  
Static Indentation ◽  
The Impact

The aim of this study was to investigate the valuable impact damage parameters from quasi-static indentation testing to access the low-velocity impact behaviour of ex-situ toughened composites by comparing low-velocity impact and quasi-static test results (the same boundary conditions). In terms of the delamination damage threshold load and indentation depth, quasi-static tests predicted the impact damage resistance well. However, only very conservative estimates of maximum load due to the final fibre failure under higher energy level were achieved. This phenomenon is attributed to two factors. First, energy during quasi-static indentation event is completely transformed or absorbed by the laminate, where it is stored elastically in panel bending or absorbed by the creation of damage, without the energy in the form of vibration, heat, inelastic behaviour of the impactor or the supports. Second, strain rate effect may have a remarkable influence on the fibre failure but on undamaged and delaminated damage.

Strength Loss in Composite Cylinders Under Impact

1988 ◽  
Vol 110 (2) ◽  
pp. 180-184 ◽  
Author(s):  
A. P. Christoforou ◽  
S. R. Swanson
Keyword(s):  
Composite Structures ◽  
Composite Plates ◽  
Strength Loss ◽  
Pressure Vessels ◽  
Fourier Series Expansion ◽  
Lateral Impact ◽  
Low Velocity ◽  
Expansion Procedure ◽  
The Impact ◽  
Composite Cylinders

The problem of strength loss in composite structures due to impact appears to be important due to the sensitivity of advanced composites to these loadings. Although a number of studies have been carried out on impact of flat composite plates, relatively little work has been done on tubular geometries such as pressure vessels despite the usage in applications. We have addressed the problem of calculating strength loss due to low velocity, lateral impact of composite cylinders. In our model we use an existing Fourier Series expansion procedure to calculate ply stresses and strains, compare these values with allowables to predict fiber breakage during the impact, and finally use fracture mechanics to predict the strength loss due to the impact. Although the model is quite simplified, the general trends of experiments appear to be represented.

Experimental Investigation of Impacted and Non-Impacted Composite Laminates under Compressive Loading

2011 ◽  
Vol 284-286 ◽  
pp. 607-610
Author(s):  
Jiang Tao Ruan ◽  
Min Shen ◽  
Jing Wei Tong ◽  
Shi Bin Wang ◽  
Francesco Aymerich ◽  
...  
Keyword(s):  
Composite Laminates ◽  
Optical Measurement ◽  
Speckle Pattern ◽  
Compressive Loading ◽  
Laminated Plates ◽  
Low Velocity Impact ◽  
Compressive Deformation ◽  
Electronic Speckle Pattern Interferometry ◽  
Low Velocity ◽  
The Impact

In this paper, the deformation measurements of impacted and non-impacted composite laminates under compressive loading are taken. [03/903]S orientated cross-ply laminated plates with impact delamination and without delamination are tested using an anti-buckling testing device in compression experiment. The delamination is induced by low-velocity impact test at the impact energy level of 3.105J. For both impacted and non-impacted specimens, the compressive deformation is measured by a carrier electronic speckle pattern interferometry (CESPI) optical measurement technique. It is found that the deformation behavior of the two specimens presents a mixed deformation mode. However, the delamination has significant effect on the compressive deformation of composite laminates.

Low Velocity Impact on Fiber Reinforced Geocomposites

2016 ◽  
Vol 827 ◽  
pp. 145-148 ◽  
Author(s):  
Sneha Samal ◽  
David Reichmann ◽  
Iva Petrikova ◽  
Bohdana Marvalova
Keyword(s):  
Impact Damage ◽  
Acoustic Vibration ◽  
Low Velocity Impact ◽  
Low Velocity ◽  
Velocity Impact ◽  
Impact Behaviour ◽  
Reinforced Composite ◽  
Before And After ◽  
Two Parameters ◽  
The Impact

Low velocity impact strength of the fabric reinforced geocomposite has investigated in this article. Various fabrics such as carbon and E-glass were considered for reinforcement in geopolymer matrix. The primary two parameters such as low velocity, impact damage modes are explained on the E-glass and carbon based fabric geocomposite. The onset mode of damage to failure mode is examined through C-scan analysis. The quality of the composite is observed using c-scan with acoustic vibration mode of sensor before and after impact test. Then the effect of fabric and matrix on the impact behaviour is discussed. Residual strength of the composite is measured to determine post impact behaviour. It has been observed that resistance properties of E-glass reinforced composite is better than carbon fabric reinforced composite.

Experimental investigation on a fully thermoplastic composite subjected to repeated impacts

2019 ◽  
Vol 233 (19-20) ◽  
pp. 6985-7002
Author(s):  
S Boria ◽  
A Scattina ◽  
G Belingardi
Keyword(s):  
Composite Laminates ◽  
Mechanical Performance ◽  
Impact Damage ◽  
Energy Levels ◽  
Thermoplastic Composite ◽  
Thermoplastic Composites ◽  
Low Velocity ◽  
Repeated Impacts ◽  
Structural Parts ◽  
The Impact

In the last years, the spread of composite laminates into the engineering sectors was observed; the main reason lies in higher values of strength/weight and stiffness/weight ratios with respect to conventional materials. Firstly, the attention was focused on fibres reinforced with thermosetting matrix. Then, the necessity to move towards low density and recyclable solutions has implied the development of composites made with thermoplastic matrix. Even if the first application of thermoplastic composites can be found into no structural parts, the replacement of metallic structural parts with such material in areas potentially subjected to impact has become worthy of investigation. Depending on the field of application and on the design geometry, in fact, some components can be subjected to repeated impacts at localized sites either during fabrication, activities of routine maintenance or during service conditions. When composite material was adopted, even though the impact damage associated to the single impact event can be slight, the accumulation of the damage over time may seriously weaken the mechanical performance of the structure. In this overview, the capability of energy absorption of a new composite completely made of thermoplastic material was investigated. This material was able to combine two conflicting requirements: the recyclability and the lightweight. In particular, repeated impacts at low velocity, on self-reinforced laminates made of polypropylene (PP), were conducted by experimental drop dart tests. Repeated impacts up to the perforation or up to 40 times were performed. In the analysis, three different energy levels and three different values of the laminate thicknesses were considered in order to analyse the damage behaviour under various experimental configurations. A visual observation of the impacted specimens was done, in order to evaluate the damage progression. Moreover, the trend of the peak force interchanged between specimen and dart and the evolution of both the absorbed energy and of the bending stiffness with the impacts number were studied. The results pointed out that the maximum load and the stiffness of the specimens tended to grow increasing the number of the repeated impacts. Such trend is opposite compared to the previous results obtained by other researchers using thermosetting composites.

Fatigue Behavior of Impacted Plain-Weave Glass/Epoxy Composites under Tensile Fatigue Loading

2005 ◽  
Vol 297-300 ◽  
pp. 1291-1296 ◽  
Author(s):  
Ki Weon Kang ◽  
Jung Kyu Kim ◽  
Heung Seob Kim
Keyword(s):  
Fatigue Life ◽  
Impact Damage ◽  
Fatigue Behavior ◽  
Fatigue Loading ◽  
Epoxy Composites ◽  
Low Velocity Impact ◽  
Low Velocity ◽  
Damage Behavior ◽  
Plain Weave ◽  
The Impact

The goals of this paper are to identify the impact damage behavior of plain-weave E-glass/epoxy composites and predict the fatigue life of the composites with impact-induced damage under constant amplitude loading. To identify these behaviors, the low velocity impact and fatigue after impact tests are performed for glass/epoxy composites having two types of fiber orientations. The impact damage behavior is dependent on the fiber orientation of the composites. The fatigue life of the impacted composites can be identified through the prediction model, which was proposed on the carbon/epoxy laminates by authors regardless of fiber orientations.

Comparison of the impact damage resistance of non-hybrid and intra-ply hybrid carbon/E-glass/polypropylene non-crimp thermoplastic composites

2018 ◽  
Vol 38 (1) ◽  
pp. 31-45 ◽  
Author(s):  
Gaye Kaya
Keyword(s):  
Damage Tolerance ◽  
Impact Damage ◽  
Low Velocity Impact ◽  
Thermoplastic Composites ◽  
Low Velocity ◽  
Impact Properties ◽  
Compression After Impact ◽  
Post Impact ◽  
The Impact ◽  
Hybrid Carbon

This study aims to compare the low-velocity impact and post-impact properties of intra-ply hybrid carbon/E-glass/polypropylene non-crimp thermoplastic composites with non-hybrid carbon/PP and E-glass/PP non-crimp thermoplastic composites. Impact test was performed at four energy levels as 15 J, 30 J, 45 J and 60 J. Post-impact properties of hybrid thermoplastic composites were tested by compression after impact method for each energy level to understand the impact damage tolerance of intra-ply hybrid carbon/E-glass/PP non-crimp thermoplastic composites. The effect of hybridization on energy absorption of composites was not significant, while C-scan results showed that the intra-ply hybrid non-crimp thermoplastic composites had smaller impact damage areas in comparison to the non-hybrid samples. Compression and compression after impact tests results confirmed that the intra-ply hybridization increased the toughness of the composite laminates. Also, the residual compression strength/modulus increased with hybridization which indicated to damage tolerance.

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