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.

A damage mechanics model for low-velocity impact damage analysis of composite laminates

2017 ◽  
Vol 121 (1238) ◽  
pp. 515-532 ◽  
Author(s):  
N. Li ◽  
P.H. Chen ◽  
Q. Ye
Keyword(s):  
Composite Laminates ◽  
Damage Mechanics ◽  
Failure Modes ◽  
Impact Damage ◽  
Matrix Cracking ◽  
Low Velocity Impact ◽  
Fracture Plane ◽  
Low Velocity ◽  
Velocity Impact ◽  
The Impact

ABSTRACTA method was developed to predict numerically the damage of composite laminates with multiple plies under low-velocity impact loading. The Puck criterion for 3D stress states was adopted to model the intralaminar damage including matrix cracking and fibre breakage, and to obtain the orientation of the fracture plane due to matrix failure. According to interlaminar delamination mechanism, a new delamination criterion was proposed. The influence of transverse and through-thickness normal stress, interlaminar shear stress and damage conditions of adjacent plies on delamination was considered. In order to predict the impact-induced damage of composite laminates with more plies quickly and efficiently, an approach, which can predict the specific damage of several plies in a single solid element, was proposed by interpolation on the strains of element integration points. Moreover, the proposed model can predict specific failure modes. A good agreement between the predicted delamination shapes and sizes and the experimental results shows correctness of the developed numerical method for predicting low-velocity impact damage on composite laminates.

scholarly journals A SEM-Based Study of Structural Impact Damage

2010 ◽  
Vol 24-25 ◽  
pp. 233-238 ◽  
Author(s):  
M.T.H. Sultan ◽  
Alma Hodzic ◽  
W.J. Staszewski ◽  
Keith Worden
Keyword(s):  
Composite Laminates ◽  
Impact Damage ◽  
Substantial Reduction ◽  
Matrix Cracking ◽  
Low Velocity Impact ◽  
Low Velocity ◽  
Fibre Pullout ◽  
Series Of Experiments ◽  
Ultimate Objective ◽  
The Impact

The ultimate objective of the current programme of work is to detect and quantify low-velocity impact damage in structures made from composite materials. There are many situations in the use of composites where an impact does not result in perforation of the material but causes damage that may not be visible, yet still causes a substantial reduction in structural properties. Impacts that do not cause perforation are usually termed low-velocity. When a composite structure undergoes such impacts, it is important to know the type and level of damage and assess the residual strength. In this study, following a systematic series of experiments on the induction of impact damage in composite specimens, Scanning Electron Microscopy (SEM) was used to inspect the topographies of the specimens at high magnification. Matrix cracking, fibre fracture, fibre pullout and delamination were the types of damage observed in the composite laminates after the low-velocity impacts. The study also conducted a (very) preliminary correlation between the damage modes and the impact energy.

A Study on Low Velocity Impact of Woven Glass/Phenolic Composite Laminates Considering Environmental Effects

2005 ◽  
Vol 297-300 ◽  
pp. 1303-1308 ◽  
Author(s):  
Jae Hoon Kim ◽  
Duck Hoi Kim ◽  
Hu Shik Kim ◽  
Byoung Jun Park
Keyword(s):  
Compressive Strength ◽  
Environmental Effects ◽  
Impact Loading ◽  
Composite Laminates ◽  
Impact Damage ◽  
Low Velocity Impact ◽  
Low Velocity ◽  
Internal Damage ◽  
The Impact ◽  
Phenolic Composite

The objectives of this study are to evaluate the internal damage and compressive residual strength of composite laminate by impact loading. To investigate the environmental effects, as-received and accelerated-aged glass/phenolic laminates are used. UT C-Scan is used to determine the impact damage characteristics and CAI tests are carried out to evaluate quantitatively the reduction of compressive strength by impact loading. The damage modes of the woven glass/phenolic laminates are evaluated. In the case of the accelerated-aged laminates, as aging time increases, initial failure energy and residual compressive strength decrease.

Analysis on Low Velocity Impact Damage and Compressive Residual Strength of Composite Laminates

2014 ◽  
Vol 566 ◽  
pp. 463-467
Author(s):  
Pu Xue ◽  
H.H. Chen ◽  
W. Guo
Keyword(s):  
Experimental Data ◽  
Residual Strength ◽  
Composite Laminates ◽  
Damage Mechanics ◽  
Impact Damage ◽  
Numerical Results ◽  
Low Velocity Impact ◽  
Low Velocity ◽  
Velocity Impact ◽  
The Impact

This paper studies the impact damage under low velocity impact for composite laminates based on a nonlinear progressive damage model. Damage evolution is described by the framework of the continuum damage mechanics. The real impact damage status of composite laminates has been used to analyze the residual compressive strength instead of assumptions on damage area after impact. The validity of the methodologies has been demonstrated by comparing the numerical results with the experimental data available in literature. The delamination area has an error of 11.3%. The errors of residual strength and compressive displacement are 8.9% and 15%, which indicate that the numerical results matched well with the experimental data.

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.

Impact Damage Behavior of Glass/Epoxy Laminates for Railway Vehicle at Low Temperature

2006 ◽  
Vol 326-328 ◽  
pp. 1793-1796
Author(s):  
Ki Weon Kang ◽  
Seung Yong Yang ◽  
J.H. Kim ◽  
Jung Kyu Kim ◽  
Heung Seob Kim ◽  
...  
Keyword(s):  
Composite Laminates ◽  
Impact Damage ◽  
Testing Machine ◽  
Impact Testing ◽  
Low Velocity Impact ◽  
Railway Vehicle ◽  
Low Velocity ◽  
Damage Resistance ◽  
Damage Behavior ◽  
The Impact

This paper deals with the damage behavior of glass/epoxy composite laminates subjected to low-velocity impact at various temperatures. For this goal, the impact tests were performed by using an instrumented impact-testing machine at three temperatures: +20°C, -10°C and -40°C. And the resultant damages were inspected through the scanning acoustic microscope (SAM). Also, based on the impact force history and the damage configuration of the laminates, the impact resistance parameters were employed to evaluate damage resistance of glass/epoxy laminates. As results, it was found that the temperature changes affect the damage resistance capacity of glass/epoxy laminates.

scholarly journals Optical Evaluation on Delamination Buckling of Composite Laminate with Impact Damage

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
J. T. Ruan ◽  
F. Aymerich ◽  
J. W. Tong ◽  
Z. Y. Wang
Keyword(s):  
Composite Laminate ◽  
Impact Damage ◽  
Testing Machine ◽  
Local Deformation ◽  
Image Correlation ◽  
Low Velocity Impact ◽  
Low Velocity ◽  
Delamination Buckling ◽  
3D Deformation ◽  
The Impact

The delamination buckling and growth behaviors of a cross-ply composite laminate with damage induced by low velocity impact are investigated optically using three-dimensional digital image correlation (3D-DIC) method. For the 3D deformation measurement, the 3D-DIC setup comprised of two CCD cameras was adopted. The rectangle specimen was impacted under the impact energy of 7.0 J using a drop-weight testing machine, and the impact damage was detected by means of X-ray nondestructive evaluation (NDE) technique. The 3D deformation field measured with the optical system clearly reveals that the delamination buckling characteristic of the specimen mainly appears local deformation mode under compression after impact test. Moreover, the behavior of delamination growth evaluated by the 3D-DIC optical method reasonably agrees with the NDE observed damage result after compression.

Acoustic Emission Analysis of Composite Laminates under Low Velocity Impact

2010 ◽  
Vol 118-120 ◽  
pp. 216-220 ◽  
Author(s):  
Hao Chen ◽  
Xiao Yan Tong ◽  
Xiang Zheng ◽  
Lei Jiang Yao
Keyword(s):  
Acoustic Emission ◽  
Composite Laminates ◽  
Damage Zone ◽  
High Energy ◽  
Matrix Cracking ◽  
Low Velocity Impact ◽  
Low Velocity ◽  
Emission Analysis ◽  
Velocity Impact ◽  
The Impact

One of the problems preventing the industrial application of composites is the lack of an efficient method to detect and discriminate among types of damage occurring during service. To solve this problem, low velocity impact experiments are carried out on T300/QY8911 composite laminates. And synchronously, the acoustic emission (AE) technique and impact monitoring systems were used to record the AE signals and the impact force. The damage evolution, damage modes and acoustic emission (AE) activity were easily detected and evaluated by the analysis of both AE waveform and impact load. In this way, the damage development process containing matrix cracking, delamination and fibers breakage is investigated. The energy release of damage are theoretically approximated and correlated with the AE energy. By the theory, the “high energy damage zone” is defined in the scatter diagrams of amplitude-frequency. It is easily to prove that the primary damage mode of “high energy damage zone” is delamination.

Nondestructive Methods for the Damage Assessment of Cylindrically Curved Composite Laminates Subjected to Low-Velocity Impact

2002 ◽  
Author(s):  
Oh-Yang Kwon ◽  
Jung-Kyu Jun ◽  
Yuris A. Dzenis
Keyword(s):  
Composite Laminates ◽  
Damage Assessment ◽  
Impact Damage ◽  
Acoustic Microscopy ◽  
Low Velocity Impact ◽  
Layer By Layer ◽  
Low Velocity ◽  
Velocity Impact ◽  
The Impact ◽  
Maximum Contact

Curved composite laminates appeared to be more vulnerable than flat ones to rapid transverse loading. Damage induced by low-velocity impact on the cylindrically curved composite laminates has been experimentally investigated. Graphite/epoxy shells with the radius of curvatures of 150 mm showed quite different impact response and damage behavior from that of flat laminate. Under the same impact energy level, the maximum contact force varied with the radius of curvatures, which is directly related to the impact damage. Delamination was distributed rather evenly at each interface along the thickness direction of curved laminates on the contrary to the case of flat laminates, where delamination is typically concentrated at the interfaces away from the impact point. Due to the presence of curvature, the acoustic microscopy could not be directly applied to the layer-by-layer assessment of delamination damage. As an alternative, the penetrant-enhanced X-radiography (PEXR) was introduced and the results from PEXR were compared with those from destructive examination of the cross-section by scanning electron microscopy.

Research on Low Velocity Impact Damage of Laminated Composite

2014 ◽  
Vol 513-517 ◽  
pp. 201-205
Author(s):  
Shu Chang Long ◽  
Ze Jin Li ◽  
Gang Kuang ◽  
Yan Bin He ◽  
Xiao Hu Yao
Keyword(s):  
Impact Damage ◽  
Laminated Composite ◽  
Matrix Cracking ◽  
Low Velocity Impact ◽  
Low Velocity ◽  
Velocity Impact ◽  
The Matrix ◽  
Bonding Properties ◽  
Cracking Zone ◽  
The Impact

Damage caused by low-velocity-impact in laminated composite will significantly reduce the strength of the structure. A new numerical model is proposed for the research on the impact induced damage of laminated composite. Multiple forms of damage within and between layers are considered in this model. The cohesive contact technology is used to simulate the bonding properties between layers. The model can describe the information of delamination more accurately and efficiently. Then, a study is carried out to investigate the relationship of delamination and matrix cracking caused by low-velocity-impact. The result reveals that the area and axis of the delamination zone is affected by the direction of the matrix cracking zone.

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