scholarly journals Prediction of the Compresion-After-Impact Strength of Thin-Skin Stiffened Composite Panels

2000 ◽  
Vol 9 (4) ◽  
pp. 096369350000900 ◽  
Author(s):  
Y. Zhuk ◽  
C. Soutis ◽  
I. Guz
Keyword(s):  
Impact Damage ◽  
Low Velocity Impact ◽  
Composite Panels ◽  
Low Velocity ◽  
Damage Initiation ◽  
Mechanics Model ◽  
Stiffened Composite Panels ◽  
Open Hole ◽  
Thin Skin ◽  
The Impact

The compressive response of thin-skin stiffened composite panels with low velocity impact damage is examined. The finite element method together with the Soutis-Fleck fracture mechanics model is used to predict damage initiation in the form of fibre microbuckling in the 0° plies, propagation and final failure; in the model the impact damage is replaced with an equivalent circular or elliptical open hole. Theoretical results are compared to experimental data and found in good agreement.

scholarly journals Palliatives for Low Velocity Impact Damage in Composite Laminates

2017 ◽  
Vol 2017 ◽  
pp. 1-16 ◽  
Author(s):  
Mubarak Ali ◽  
S. C. Joshi ◽  
Mohamed Thariq Hameed Sultan
Keyword(s):  
Composite Laminates ◽  
Impact Damage ◽  
Laminated Composites ◽  
Low Velocity Impact ◽  
Normal Operation ◽  
Fibre Reinforcement ◽  
Low Velocity ◽  
Velocity Impact ◽  
Damage Initiation ◽  
The Impact

Fibre reinforced polymer laminated composites are susceptible to impact damage during manufacture, normal operation, maintenance, and/or other stages of their life cycle. Initiation and growth of such damage lead to dramatic loss in the structural integrity and strength of laminates. This damage is generally difficult to detect and repair. This makes it important to find a preventive solution. There has been abundance of research dealing with the impact damage evolution of composite laminates and methods to mitigate and alleviate the damage initiation and growth. This article presents a comprehensive review of different strategies dealing with development of new composite materials investigated by several research groups that can be used to mitigate the low velocity impact damage in laminated composites. Hybrid composites, composites with tough thermoplastic resins, modified matrices, surface modification of fibres, translaminar reinforcements, and interlaminar modifications such as interleaving, short fibre reinforcement, and particle based interlayer are discussed in this article. A critical evaluation of various techniques capable of enhancing impact performance of laminated composites and future directions in this research field are presented in this article.

Finite Element Analysis of Stiffened Composite Panels Subjected by Low-Velocity Impact

2014 ◽  
Vol 644-650 ◽  
pp. 4726-4730
Author(s):  
Wen Chao Zhang ◽  
Yuan Guo ◽  
Zhi Dong Guan ◽  
Xia Guo ◽  
Wei He ◽  
...  
Keyword(s):  
Damage Mechanics ◽  
Low Velocity Impact ◽  
Good Prediction ◽  
Fe Model ◽  
Composite Panels ◽  
Low Velocity ◽  
Element Analysis ◽  
Interface Elements ◽  
Stiffened Composite Panels ◽  
The Impact

In this paper, the low-velocity performance of stiffened composite panels is investigated experimentally and numerically. In order to illustrate the effect of the stiffener, a number of plain laminates with same lay-up of the skin were impacted in various energies. Progressive damage models based on continuum damage mechanics (CDM) were used in combination with cohesive interface elements to predict the structural response and fracture mechanics of stiffened composite panels. The constitutive mode was implemented into the ABAQUS/Explicit FE code by user-defined material subroutines (VUMAT). The developed FE model made a good prediction about the structural impact response of stiffened panels over the rang of impact energies examined. Very good agreement was achieved between the extent of damage predicted around the impact site and the damage detected by non-destructive technique (NDT) ultrasonic C-scan of the panels.

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.

Passive Damage Detection of Natural Fibre Reinforced Composites Using Sensor Response Data

2014 ◽  
Vol 534 ◽  
pp. 17-23 ◽  
Author(s):  
M. Zaleha ◽  
Shahruddin Mahzan ◽  
M.I. Idris
Keyword(s):  
Lead Zirconate Titanate ◽  
Impact Damage ◽  
Lead Zirconate ◽  
Optical Microscope ◽  
Natural Fibre ◽  
Low Velocity Impact ◽  
Low Velocity ◽  
Damage Initiation ◽  
Response Data ◽  
Sensor Signals

This paper presents the detection of impact damage in a natural fibre reinforced composite plate under low velocity impact damage. Lead Zirconate Titanate (PZT) sensors were placed at ten different positions on each plate in order to record the response signals. The response signals captured from each sensor were collected for impacts performed by a data acquisition system. The impacted plates were examined with optical microscope to examine the damaged areas. It was found that the damaged size grew proportionally with impact force. The results also revealed that PZT sensors can be used to detect the damage extent with the waveform of sensor signals implying the damage initiation and propagation which detected above the damage force of 150N.

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.

scholarly journals Determination of Impact Damage in CFRP via PVDF Signal Analysis with Support Vector Machine

Materials ◽  
2020 ◽  
Vol 13 (22) ◽  
pp. 5207
Author(s):  
Hyun-Taik Oh ◽  
Jong-Ick Won ◽  
Sung-Choong Woo ◽  
Tae-Won Kim
Keyword(s):  
Support Vector Machine ◽  
Vinylidene Fluoride ◽  
Impact Damage ◽  
Low Velocity Impact ◽  
Electrical Performance ◽  
Support Vector ◽  
Discrete Wavelet ◽  
Low Velocity ◽  
Damage State ◽  
The Impact

Carbon fiber reinforced plastics (CFRPs) have high specific stiffness and strength, but they are vulnerable to transverse loading, especially low-velocity impact loadings. The impact damage may cause serious strength reduction in CFRP structure, but the damage in a CFRP is mainly internal and microscopic, that it is barely visible. Therefore, this study proposes a method of determining impact damage in CFRP via poly(vinylidene fluoride) (PVDF) sensor, which is convenient and has high mechanical and electrical performance. In total, 114 drop impact tests were performed to investigate on impact responses and PVDF signals due to impacts. The test results were analyzed to determine the damage of specimens and signal features, which are relevant to failure mechanisms were extracted from PVDF signals by means of discrete wavelet transform (DWT). Support vector machine (SVM) was used for optimal classification of damage state, and the model using radial basis function (RBF) kernel showed the best performance. The model was validated through a 4-fold cross-validation, and the accuracy was reported to be 92.30%. In conclusion, impact damage in CFRP structures can be effectively determined using the spectral analysis and the machine learning-based classification on PVDF signals.

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 Static Residual Tensile Strength Response of GFRP Composite Laminates Subjected to Low-Velocity Impact

2020 ◽  
Vol 10 (16) ◽  
pp. 5480
Author(s):  
Jong-Il Kim ◽  
Yong-Hak Huh ◽  
Yong-Hwan Kim
Keyword(s):  
Tensile Strength ◽  
Composite Laminates ◽  
Impact Damage ◽  
Image Correlation ◽  
Matrix Cracking ◽  
Low Velocity Impact ◽  
Stress Concentrations ◽  
Low Velocity ◽  
Full Field ◽  
The Impact

The dependency of the static residual tensile strength for the Glass Fiber-Reinforced Plastic (GFRP) laminates after impact on the impact energy level and indent shape is investigated. In this study, two different laminates, unidirectional, [0°2]s) and TRI (tri-axial, (±45°/0°)2]s), were prepared using the vacuum infusion method, and an impact indent on the respective laminates was created at different energy levels with pyramidal and hemispherical impactors. Impact damage patterns, such as matrix cracking, delamination, debonding and fiber breakage, could be observed on the GFRP laminates by a scanning electron microscope (SEM), and it is found that those were dependent on the impactor head shape and laminate structure. Residual in-plane tensile strength of the impacted laminates was measured and the reduction of the strength is found to be dependent upon the impact damage patterns. Furthermore, in this study, stress concentrations in the vicinity of the indents were determined from full-field stress distribution obtained by three-dimensional Digital Image Correlation (3D DIC) measurement. It was found that the stress concentration was associated with the reduction of the residual strength for the GFRP laminates.

scholarly journals Ultrasonic Analysis of Damage in CFRP Resulting from Static Indentation and Low Velocity Impact

1993 ◽  
Vol 2 (3) ◽  
pp. 096369359300200
Author(s):  
H. Kaczmarek
Keyword(s):  
Impact Testing ◽  
Low Velocity Impact ◽  
Ultrasonic Tomography ◽  
Transverse Impact ◽  
Low Velocity ◽  
Velocity Impact ◽  
Testing Procedures ◽  
Damage Initiation ◽  
Static Indentation ◽  
The Impact

In order to reduce hidden damage caused in CFRP by low velocity transverse impact, testing procedures must be established by understanding the impact phenomena and the roles of various parameters on damage initiation and growth. Hence, composite plates were stressed and an original method, “ultrasonic tomography,” was applied to detect delaminations on the interfaces. The results show the similarity of the damage growth resulting from static indentation and low velocity impact.

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