الفهرس 
Chapter One: IntroductionOnly 14 pages are availabe for public view
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Abstract
The mechanical behavior of epoxy reinforced by different types of woven fibers at three different strain rate was studied under tension and bending loads. The reinforcements used were: woven glass fibers (volume fractions: 8%, 16%, 24%, 32%, and 40%), woven carbon fibers (volume fractions: 8%, 16%, 24%, and 32%), and woven hybrid (carbon/glass) fibers (volume fractions: 16%, 32%, and 48%). The composites were manufactured using the compression molding technique.
Pure (unreinforced) epoxy specimens were tested as a reference material. The fracture behavior of the investigated specimens was studied both macroscopically, and using (Amscop) microscopy. It was found that under tensile loads, with increasing the volume fraction the ultimate tensile strength increase at all type of reinforcement composites. In the same way increasing the strain rate in the same volume fraction increases the ultimate tensile strength.
The modulus of elasticity of epoxy-reinforced by fibers continued to increase as a function of fiber volume fraction. Similar trend of improvements were observed for the other mechanical properties under tensile loads.
Under bending loads, flexure strength showed significant improvement as a function of glass fiber volume fraction. At the same reinforcement volume fraction, hybrid composites (carbon fiber in tension side) gave the highest mechanical properties, followed by carbon fiber, followed by glass fiber, while hybrid composites (glass fiber in tension side) showed lowest improvement.
Fiber pull-out and debonding are the main fracture mechanisms for glass fiber reinforced epoxy, while interlaminar shearing is the main mechanism for carbon fiber composites. Hybrid composites showed a mixed mode mechanism. The fracture process in bending proceeded in stages from the tension side inwards towards the compression side.