Low Velocity Impact Studies on a 4-Ply Knitted Kevlar Fabric Reinforced Epoxy Composite

2002 ◽  
Vol 21 (2) ◽  
pp. 121-138 ◽  
Author(s):  
C. T. Lim ◽  
V. B. C. Tan ◽  
S. Ramakrishna ◽  
J. B. K. Lee
Keyword(s):  
Epoxy Composite ◽  
Impact Resistance ◽  
Matrix Cracking ◽  
Low Velocity Impact ◽  
Normal Impact ◽  
Low Velocity ◽  
Fibre Breakage ◽  
Significant Difference ◽  
Impact Energies ◽  
Fibre Matrix

Four-ply knitted Kevlar fabric reinforced epoxy composites with three different stacking sequences were subjected to normal impact of up to 10 J using a hemispherical steel impactor. Similar modes of damage were observed from impacts on all three different stacking sequences where damage progressed from matrix cracking and fibre/matrix debonding at low impact energies to fibre breakage and eventual through-thickness cracks at higher impact energies. A critical mode of damage occurred at about 4.5 J where there was a sudden deterioration of impact resistance due to fibre breakage at the top and bottom plys. The only significant difference among composites of different stacking sequences subjected to low velocity impacts of similar magnitude was the propagation of through-thickness cracks at impact energy larger than 5 J.

Low Velocity Impact Resistance of CPVC Pipes Exposed to Natural Outdoor Weathering Conditions

2012 ◽  
Vol 445 ◽  
pp. 959-964
Author(s):  
Z. Khan ◽  
Necar Merah ◽  
A. Bazoune ◽  
S. Furquan
Keyword(s):  
Impact Resistance ◽  
Outdoor Exposure ◽  
Impact Testing ◽  
Low Velocity Impact ◽  
Pipe Material ◽  
Low Velocity ◽  
Impact Energies ◽  
The Impact ◽  
Impact Events ◽  
Outdoor Weathering

Low velocity drop weight impact testing of CPVC pipes was conducted on 160 mm long pipe sections obtained from 4-inch (100 mm) diameter schedule 80 pipes. Impact test were carried out for the base (as received) pipes and after their exposure to out door natural weathering conditions in Dhahran, Saudi Arabia. The results of the impact testing on the natural (outdoor exposure) broadly suggest that the natural outdoor exposures produce no change in the impact resistance of CPVC pipe material for the impact events carrying low incident energies of 10 and 20J. At the impact energies of 35 and 50J the natural outdoor exposures appear to cause appreciable degradation in the impact resistance of the CPVC pipe material. This degradation is noted only for the longer exposure periods of 12 and 18 months.

scholarly journals Effect of Fibres on the Failure Mechanism of Composite Tubes under Low-Velocity Impact

Materials ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4143
Author(s):  
Jie Xiao ◽  
Han Shi ◽  
Lei Tao ◽  
Liangliang Qi ◽  
Wei Min ◽  
...  
Keyword(s):  
Failure Mechanism ◽  
Impact Resistance ◽  
Low Velocity Impact ◽  
Low Velocity ◽  
Basalt Fibre ◽  
Composite Tubes ◽  
Velocity Impact ◽  
Fibre Breakage ◽  
Reinforced Composite ◽  
The Impact

Filament-wound composite tubular structures are frequently used in transmission systems, pressure vessels, and sports equipment. In this study, the failure mechanism of composite tubes reinforced with different fibres under low-velocity impact (LVI) and the radial residual compression performance of the impacted composite tubes were investigated. Four fibres, including carbon fiber-T800, carbon fiber-T700, basalt fibre, and glass fibre, were used to fabricate the composite tubes by the winding process. The internal matrix/fibre interface of the composite tubes before the LVI and their failure mechanism after the LVI were investigated by scanning electric microscopy and X-ray micro-computed tomography, respectively. The results showed that the composite tubes mainly fractured through the delamination and fibre breakage damage under the impact of 15 J energy. Delamination and localized fibre breakage occur in the glass fibre-reinforced composite (GFRP) and basalt fibre-reinforced composite (BFRP) tubes when subjected to LVI. While fibre breakage damage occurs globally in the carbon fibre-reinforced composite (CFRP) tubes. The GFRP tube showed the best impact resistance among all the tubes investigated. The basalt fibre-reinforced composite (BFRP) tube exhibited the lowest structural impact resistance. The impact resistance of the CFRP-T700 and CFRP-T800 tube differed slightly. The radial residual compression strength (R-RCS) of the BFRP tube is not sensitive to the impact, while that of the GFRP tube is shown to be highly sensitive to the impact.

The Effect of Hybridization of the Glass Fiber-Flexible Modified Epoxy and Rigid Epoxy Composite Properties under Low-Velocity Impact

2012 ◽  
Vol 626 ◽  
pp. 255-259
Author(s):  
Siti Nur Liyana Mamauod ◽  
Mohd Hanafiah Abidin ◽  
Ahmad Zafir Romli
Keyword(s):  
Glass Fiber ◽  
Epoxy Composite ◽  
Impact Resistance ◽  
Low Velocity Impact ◽  
Low Velocity ◽  
Velocity Impact ◽  
Rigid Polymer ◽  
Brittle Phase ◽  
The Impact ◽  
Modified Epoxy

In the present study, experiment was carried out to investigate the impact properties of flexible and rigid polymer reinforced with E-glass fiber, under low velocity impact. The experimental work includes preparing the cured glassflexible modified epoxy and placed it onto the uncured glass-epoxy composite samples. The experimental results prove that the hybridization improves the impact strength of laminates. The flexibility segments that were introduced into the epoxy system increased the penetration impact resistance value. Hence more impact energy is required to perforate the samples compared to epoxy composite system which is brittle phase.

scholarly journals Impact Resistance of Fibre Reinforced Composite Railway Freight Tank Wagons

2021 ◽  
Vol 5 (6) ◽  
pp. 152
Author(s):  
George Edward Street ◽  
Preetum Jayantilal Mistry ◽  
Michael Sylvester Johnson
Keyword(s):  
Composite Structures ◽  
Failure Modes ◽  
Biaxial Loading ◽  
Impact Damage ◽  
Impact Resistance ◽  
Matrix Cracking ◽  
Low Velocity Impact ◽  
Low Velocity ◽  
Fibre Direction ◽  
Reinforced Composite

The use of fibre reinforced composite materials is one method by which the lightweighting of rail vehicles can be achieved. However, the issue of impact damage, amongst other challenges, limits their safety certification. This issue is accentuated by the high levels of loading a rail vehicle may be subjected to during service. This paper addresses the significance of pre-tension on large composite structures, specifically for a composite redesign of a pressure vessel for a freight tank wagon. Preloading was determined to be detrimental to the overall impact resistance of a large composite vessel. At 15.71 J of impact energy, there was a 22% increase in mean absorbed energy for a uniaxially loaded panel over an unloaded panel. However, there was only a 4% difference in penetration depth between uniaxial and biaxial loading. A novel finding from these results is that the effects of preloading are more profound if the loading does not act parallel to a principal fibre direction. Matrix cracking and delaminations are the most common failure modes observed for specimens under low-velocity impact and are intensified by preload.

scholarly journals A Comprehensive Numerical Investigation on the Mechanical Performance of Hybrid Composite Tidal Current Turbine under Accidental Impact

2020 ◽  
Vol 17 (4) ◽  
pp. 8338-8350
Author(s):  
H. Laaouidi ◽  
M. Tarfaoui ◽  
M. Nachtane ◽  
M. Trihi ◽  
O. Lagdani
Keyword(s):  
Hybrid Composite ◽  
Mechanical Performance ◽  
Impact Resistance ◽  
Leading Edge ◽  
Matrix Cracking ◽  
Low Velocity Impact ◽  
Low Velocity ◽  
Internal Surfaces ◽  
Tidal Turbine ◽  
The Impact

The composite tidal turbine nozzle can be exposed to impact loads during maintenance or installation operations, which may result in invisible damage. Therefore, it is very important to analyse the induced damage in order to conceive hybrid composite nozzles with better resistance to damage. The low-velocity impact behaviour (LVI) of a carbon/glass hybrid composite nozzle has been investigated based on this motivation. The configurations of stacking sequences were constituted of glass and carbon fibers. The results acquired were compared between five various laminated. Indeed, the impact was studied in the leading edge region of the nozzle. The damaged laminates were inspected by the finite element method (FEM) based on Hashin failure criterion using the ABAQUS software. The energy conservation of the nozzle was verified to validate the numerical model. Futhermore, the effect of accidental impact on dynamic response and the damage induced on a hybrid composite nozzle have been investigated. According to results, the formation of damage like matrix cracking on the external/internal surfaces and radial cracking may occur. In addition, the hybrid nozzle with CCC (carbon/carbon/carbon), and CGG (carbon/glass/glass) stacking has greater impact resistance compared to other configurations.

Influence of nanoclay and incident energy on impact resistance of S2-glass/epoxy composite laminates subjected to low velocity impact

2016 ◽  
Vol 8 (2) ◽  
pp. 174-179 ◽  
Author(s):  
P. Rama Subba Reddy ◽  
T. Sreekantha Reddy ◽  
I. Srikanth ◽  
P. Ghosal ◽  
V. Madhu ◽  
...  
Keyword(s):  
Composite Laminates ◽  
Incident Energy ◽  
Epoxy Composite ◽  
Impact Resistance ◽  
Low Velocity Impact ◽  
Low Velocity ◽  
Velocity Impact
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