Effects of Hydrophobic Barrier Films on the Mechanical Properties of Fiber Reinforced Composites Immersed in Water

2011 ◽  
Author(s):  
E. Kececi ◽  
R. Asmatulu
Keyword(s):  
Mechanical Properties ◽  
Moisture Absorption ◽  
Uv Light ◽  
Fiber Reinforced Composites ◽  
Reinforced Composites ◽  
Fiber Reinforced ◽  
Bending Tests ◽  
Barrier Films ◽  
Hydrophobic Barrier ◽  
Wide Range

Fiber reinforced composites are subjected to a wide range of mechanical loads and environmental conditions, such as wind, high/low temperature, moisture, UV light and aggressive solvents. Compared to other structural materials, polymers can absorb more moisture and UV light from outside environment and lose their material properties (e.g., mechanical, electrical, surface and thermal) and thus the service life. In this study, hydrophobic barrier films including polyvinylfluoride (PVF) and polyether ether ketone (PEEK) were applied on the carbon, Kevlar, and glass fiber reinforced epoxy resin composites (laminate and sandwich structures), and then the effects of moisture absorption on those films were investigated in detail. The coupons were immersed in water for a number of days in order to determine the changes in mechanical properties of the composites. Three point bending tests were applied to the laminate composites, while four point bending tests were conducted on the Nomex sandwich structured composites. We found that moisture absorption could be eliminated by using these hydrophobic films. We found that PEEK film could be an alternative barrier film for the aircraft industry.

Microstructures and Mechanical Properties of Natural Fibers

2008 ◽  
Vol 33-37 ◽  
pp. 553-558 ◽  
Author(s):  
Yan Li ◽  
Yan Ping Hu ◽  
Chun Jing Hu ◽  
Ye Hong Yu
Keyword(s):  
Mechanical Properties ◽  
Moisture Absorption ◽  
Natural Fiber ◽  
Natural Fibers ◽  
Fiber Reinforced Composites ◽  
Reinforced Composites ◽  
Fiber Reinforced ◽  
Specific Strength ◽  
Mechanical Performances ◽  
Set Up

Natural fibers are excellent substitute materials for man made fibers in making fiber reinforced composites due to their high specific strength and modulus, low density, low price, easy availability in some countries, recyclable and degradable properties. They have raised great attentions among material scientists and engineers in the past decade. Many researches have been conducted to study the mechanical properties, especially interfacial properties of natural fiber reinforced composites. However, the properties, such as mechanical performances, moisture absorption behaviors, et. al of natural fibers themselves have been seldom investigated. Knowing the relationship between microstructures and properties of natural fibers are important for understanding the bulk properties of natural fiber composites and also good instructions for designing bio-mimic materials. In this study, four kinds of natural fibers which were extracted from different plant sources were investigated. The microstructures of these natural fibers were revealed with the aid of optical microscopy. Microstructure models were thereof set up and mechanical properties for the representative volume element were assumed. Fiber bundle fracture models together with probability statistics analysis were employed to calculate the mechanical properties of natural fibers. The results were compared with the experimental measurements. Different mechanical behaviors of natural fibers which were functioned differently in the nature were clearly explained by the above studies

Dynamic Mechanical Performance of Natural Fiber Reinforced Composites: A Brief Review

2021 ◽  
Author(s):  
Battula Durga Siva Deeraj ◽  
Kuruvilla Joseph ◽  
Jitha Santhakumari Jayan ◽  
Appukuttan Saritha
Keyword(s):  
Mechanical Properties ◽  
Composite Materials ◽  
Mechanical Performance ◽  
Natural Fiber ◽  
Fiber Reinforced Composites ◽  
Reinforced Composites ◽  
Fiber Reinforced ◽  
Dynamic Mechanical ◽  
Wide Range ◽  
Structural Applications

Natural fiber reinforced polymer composite is a much focused area of study owing to its environmentally friendly nature and good mechanical properties. These composites offer comparable mechanical properties to that of steel and other composite materials. Dynamic mechanical analysis is a widely used technique to investigate the mechanical performance of fiber reinforced composites at a wide range of temperatures. Using this technique, the thermal transitions and damping properties of fiber reinforced composites too can be studied. These natural fiber composites are widely employed in structural applications in many industries. Here, in this short review we have presented the recent works on the dynamic properties of natural fiber reinforced composite materials with an essence of the influencing factors.

scholarly journals EFFECTS OF POROSITY ON ULTRASONIC CHARACTERISTIC PARAMETERS AND MECHANICAL PROPERTIES OF GLASS FIBER REINFORCED COMPOSITES

2012 ◽  
Vol 06 ◽  
pp. 646-651 ◽  
Author(s):  
Wen Ma ◽  
Fushun Liu
Keyword(s):  
Mechanical Properties ◽  
Ultrasonic Attenuation ◽  
Ultrasonic Inspection ◽  
Fiber Reinforced Composites ◽  
Metallographic Analysis ◽  
Void Content ◽  
Reinforced Composites ◽  
Fiber Reinforced ◽  
Characteristic Parameters ◽  
Distribution Shape

Voids are inevitable in the fabrication of fiber reinforced composites and have a detrimental impact on mechanical properties of composites. Different void contents were acquired by applying different vacuum bag pressures. Ultrasonic inspection and ablation density method were adopted to measure the ultrasonic characteristic parameters and average porosity, the characterization of voids' distribution, shape and size were carried out through metallographic analysis. Effects of void content on the tensile, flexural and interlaminar shear properties and the ultrasonic characteristic parameters were discussed. The results showed that, as vacuum bag pressure went from -50kPa to -98kPa, the voids content decreased from 4.36 to 0.34, the ultrasonic attenuation coefficient decreased, but the mechanical strengths all increased.

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