Title: Tensile Properties of Stretch Broken Carbon Fiber Prepreg
Authors: Dalton B. Nold, Dilpreet S. Bajwa, Douglas Cairns, Roberta Amendola, Cecily Ryan, Chris Ridgard
Abstract: Continuous carbon fiber is known to be a superior material for its strength, stiffness, and high strength-to-weight ratio where all these properties rival titanium. A major drawback with continuous carbon fiber is that it is not versatile in forming deep drawn geometries, which can require much more convoluted manufacturing techniques resulting in expensive components. To overcome this issue, a type of carbon fiber with a random discontinuous fiber alignment called stretch broken carbon fiber (SBCF) is proposed. SBCF has potential to form parts with complex geometries with comparable or better mechanical properties (strengths and stiffness) to that of continuous carbon fiber. The Montana State University has been able to manufacture their own version of SBCF using a new propriety technology. Research is being conducted to understand how carbon fiber prepreg tow reacts to tensile forming loads at high dwelling temperatures using Solvay CYCOM® 977-3 and Hexcel HexPly® 8552 epoxy resin systems. True stress and strain curves have been developed at the resin’s respective de-bulking temperatures, which showed strain softening behavior. This can be explained considering as the resin heats up, it acts as a lubricant with respect to the load being applied and helping fibers to slide. Future work will be to investigate whether a quasi-isotropic sample layup will produce the same strain softening behavior or exhibit a different mode.
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Conference: CAMX 2022
Publication Date: 2022/10/17
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