Effects of UV Light and Moisture Absorption on the Impact Resistance of Three Different Carbon Fiber-Reinforced Composites

2014 ◽  
Author(s):  
V. Patlolla ◽  
J. George ◽  
Soo-Han Loo ◽  
R. Asmatulu
Keyword(s):  
Carbon Fiber ◽  
Moisture Absorption ◽  
Uv Light ◽  
Load Capacity ◽  
Contact Angles ◽  
Impact Testing ◽  
Impact Response ◽  
Uv Exposure ◽  
Impact Behavior ◽  
The Impact

The purpose of this research was to determine the influence of material properties on the impact response of a laminate, whereby specimens were fabricated and cured under a vacuum and high temperature using three types of pre-impregnated (prepreg), carbon fibers, namely unidirectional fiber, plain weave woven fiber, and non-crimp fiber (NCF). Each carbon fiber panel, usually known for its low-impact properties, of 16 plies underwent impact testing using a low-velocity impactor and visual damage inspection by C-scan in order to measure the damage area and depth, before and after impact testing. These panels were treated with UV exposure and moisture conditioning for 20 days each. Water contact angles were taken into consideration to determine the hydrophobicity and hydrophillicity of the respective prepreg materials. Experimental results and damage analysis showed that UV exposure and moisture conditioning showcased the variation in impact response and behavior, such as load-carrying capacity, absorbed energy, and impact energy of the carbon fiber panels. This study illustrates that non-crimp carbon fiber laminates were far more superior relative to load capacity than woven and unidirectional laminates, with the NCF-AS laminate exhibiting the highest load capacity of 17,244 lb/in (pre-UV) with only 0.89% decrease after UV exposure. This same laminate also had a 1.54% decrease in sustaining impact and 31.4% increase in wettability of the panel. Moreover, the study shows how symmetric and asymmetric stacking sequences affect the impact behavior of non-crimp fiber laminates. These results may be useful for expanding the capacity of carbon fiber, lowering costs, and growing new markets, thus turning carbon fiber into a viable commercial product.

scholarly journals Effects of temperature and impactor nose diameter on the impact behavior of PA6 and PP thermoplastic composites

2018 ◽  
Vol 51 (1) ◽  
pp. 64-74 ◽  
Author(s):  
Akar Dogan ◽  
Yusuf Arman
Keyword(s):  
Load Capacity ◽  
Testing Machine ◽  
Polyamide 6 ◽  
Impact Testing ◽  
Impact Behavior ◽  
Thermoplastic Composites ◽  
Test Machine ◽  
Effects Of Temperature ◽  
Impact Energies ◽  
The Impact

In this study, the effects of temperature and impactor nose diameter on the impact behavior of woven glass-reinforced polyamide 6 (PA6) and polypropylene (PP) thermoplastic composites were investigated experimentally. Impact energies are chosen as 10, 30, 50, 70, 90, 110, 130, and 170 J. The thickness of composite materials is 4 mm. Impact tests were performed using a drop weight impact testing machine, CEAST-Fractovis Plus, and the load capacity of test machine is 22 kN. Hemispherical impactor nose diameter of 12, 7, and 20 mm were used as an impactor. The tests are conducted at room temperature (20°C and 75°C). As a result, the PP composites of the same thickness absorbed more energy than PA6 composites. The amount of absorbed energy of PP and PA6 composites decreased with temperature.

Side Impact Testing and Analyses of Unpressurized Tank Cars

2015 ◽  
Author(s):  
Steven W. Kirkpatrick ◽  
Robert A. MacNeill ◽  
Francisco Gonzalez ◽  
Przemyslaw Rakoczy
Keyword(s):  
Structural Integrity ◽  
The United States ◽  
Impact Testing ◽  
Side Impact ◽  
Impact Response ◽  
Impact Behavior ◽  
Pressure Tank ◽  
The Government ◽  
Tank Pressure ◽  
The Impact

There has been significant research in recent years to analyze and improve the impact behavior and puncture resistance of railroad tank cars. Ultimately, the results of this work will be used by the Government regulatory agencies in the United States and Canada to establish performance-based testing requirements and to develop methods to evaluate the crashworthiness and structural integrity of different tank car designs. This paper describes results of recent side impact testing and corresponding analyses using detailed finite element analyses (FEA). The test and analyses were performed to evaluate the side impact puncture performance of DOT-111 tank cars. The tank car was filled with water to approximately 97 percent of the volume. The tank was then sealed but not pressurized. The tank car was impacted at the Transportation Technology Center, Inc. by a 297,125-pound ram car with 12-by 12-inch ram head fitted to the ram car impacted the tank center. The analyses were on overall good agreement with the measured impact response. The lading was found to play a more significant role in the impact response than in previous testing and analyses of pressure tank cars. This is not surprising considering the reduced structural stiffness of the tanks compared to thicker pressure tank cars and the reduced effective stiffness from the initially unpressurized tank at impact. The smaller outage volume also contributes to a dramatic increase in the tank pressure as the dent formation reduces the tank volume and compresses the contents of the tank.

Analysis and Development of Performance-Based Requirements for Railroad Tank Cars

2014 ◽  
Author(s):  
Steven W. Kirkpatrick ◽  
Robert A. MacNeill ◽  
Francisco Gonzalez
Keyword(s):  
Structural Integrity ◽  
The United States ◽  
Impact Testing ◽  
Impact Behavior ◽  
Safety Regulations ◽  
Significant Research ◽  
The Government ◽  
Current Impact ◽  
Test Requirements ◽  
The Impact

There has been significant research in recent years to analyze and improve the impact behavior and puncture resistance of railroad tank cars. Ultimately, the results of this work will be used by the Government regulatory agencies in the United States and Canada to establish performance-based testing requirements and to develop methods to evaluate the crashworthiness and structural integrity of different tank car designs. This paper describes analyses of current impact testing requirements and impact test methodologies using detailed finite element analyses (FEA). The results of these analyses are used to identify characteristics of the test methodologies that are desirable or undesirable for the test requirements in future tank car safety regulations.

Effect of superelastic shape memory alloy wires on the impact behavior of carbon fiber reinforced in situ polymerized poly(butylene terephthalate) composites

2011 ◽  
Vol 65 (5) ◽  
pp. 863-865 ◽  
Author(s):  
J. Aurrekoetxea ◽  
J. Zurbitu ◽  
I. Ortiz de Mendibil ◽  
A. Agirregomezkorta ◽  
M. Sánchez-Soto ◽  
...  
Keyword(s):  
Carbon Fiber ◽  
Shape Memory Alloy ◽  
Shape Memory ◽  
Impact Behavior ◽  
Fiber Reinforced ◽  
Butylene Terephthalate ◽  
Carbon Fiber Reinforced ◽  
The Impact

Tank Car Puncture Analyses for Various Impactors and Impact Conditions

2013 ◽  
Author(s):  
Steven W. Kirkpatrick ◽  
Francisco Gonzalez ◽  
Karl Alexy
Keyword(s):  
Finite Element ◽  
Research Program ◽  
Impact Testing ◽  
Impact Behavior ◽  
Finite Element Analyses ◽  
Damage And Failure ◽  
Wide Range ◽  
Significant Research ◽  
Detailed Simulation ◽  
The Impact

There has been significant research in recent years to analyze and improve the impact behavior and puncture resistance of railroad tank cars. Much of this research has been performed using detailed nonlinear finite element analyses supported by full scale impact testing. This use of detailed simulation methodologies has significantly improved our understanding of the tank impact behaviors and puncture prediction. However, the evaluations in these past studies were primarily performed for a few idealized impact scenarios. This paper describes a research program to evaluate railroad tank car puncture behaviors under more general impact conditions. The approach used in this research program was to apply a tank impact and puncture prediction capability using detailed finite element analyses (FEA). The analysis methodologies apply advanced damage and failure models that were validated by series of material tests under various loading conditions. In this study, the analyses were applied to investigate the tank puncture behaviors for a wide range of impact conditions.

UNCERTAINTY QUANTIFICATION FOR THE MANUFACTURING OF CARBON FIBER/VINYL ESTER LAMINATES

2021 ◽  
Author(s):  
ZACKERY NIETO ◽  
ALEJANDRA CASTELLANOS
Keyword(s):  
Carbon Fiber ◽  
Uncertainty Quantification ◽  
Manufacturing Process ◽  
Vinyl Ester ◽  
Weight Ratio ◽  
Filament Winding ◽  
Impact Response ◽  
Distribution Model ◽  
Cfrp Composites ◽  
The Impact

Carbon fiber reinforced polymer (CFRP) composites are lightweight materials with a high stiffness-to-weight ratio and high strength-to-weight ratio. CFRP composites consist of two constituents: reinforcement and matrix. The reinforcement consists of carbon fibers and the matrix generally consists of a thermoset or thermoplastic resins. Through choices made between these two constituents, lightweight composites can be custom-tailored to fit specific criteria, including, but not limited to, water resistance for naval vessels, thermal resistance to negate environmental degradation, and UV resistance to negate UV degradation. Many uncertainties can arise with such a vast capability in adaptation depending on material choice, manufacturing methods (vacuum assisted resin transfer molding VARTM, layup, and filament winding), and post-manufacturing processes. These uncertainties can build upon one another leading to less accurate theoretical applications when compared to their real-life counterpart. The purpose of this project is to create an indepth uncertainty quantification (UQ) analysis based on vinyl-ester resin as a preliminary report for a future carbon fiber/vinyl-ester composite UQ analysis. To properly ascertain the magnitude of uncertainty during the manufacturing process, the resin to hardener ratio and cure time were studied to understand their effect on the impact response of vinyl ester samples. Vinyl ester specimens were impacted with an impact energy of 3.3 J to produce barely visible damage (BVID) on the samples. Energy, force, displacement and time were collected for analysis. Using a Monte Carlo simulation, a probability distribution model was generated to understand the effects and UQ influence of the manufacturing process in the impact response of vinyl ester specimens.

scholarly journals Improved impact response of hygrothermally conditioned carbon/epoxy woven composites

2016 ◽  
Vol 23 (6) ◽  
pp. 699-710 ◽  
Author(s):  
Yucheng Zhong ◽  
Sunil Chandrakant Joshi
Keyword(s):  
Carbon Fiber ◽  
Impact Resistance ◽  
Impact Testing ◽  
Low Velocity Impact ◽  
Elastic Response ◽  
Woven Composites ◽  
Low Velocity ◽  
Hygrothermal Conditioning ◽  
The Impact ◽  
Carbon Fiber Epoxy

AbstractThe effects of hygrothermal conditioning and moisture on the impact resistance of carbon fiber/epoxy composite laminates were investigated. Specimens were fabricated from carbon fiber/epoxy woven prepreg materials. The fabricated specimens were either immersed in water at 80°C or subjected to hot/wet (at 80°C in water for 12 h) to cold/dry (at -30°C in a freezer for 12 h) cyclic hygrothermal conditions, which resulted in different moisture contents inside the laminates. It was found that the absorbed moisture did not migrate out from composite materials at -30°C. Neither of the hygrothermal conditions in this study had detrimental effects on the microstructure of the laminates. Low-velocity impact testing was subsequently conducted on the conditioned specimens. When attacked by the same level of impact energy, laminates with different moisture levels experienced different levels of impact damage. Moisture significantly alleviated the extent of damage in carbon fiber/epoxy woven laminates. The elastic response of the laminate under impact was improved after hygrothermal conditioning. The mechanism behind the improved impact resistance after absorbing moisture was proposed and deliberated.

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