Dynamic response and modeling of a carbon fiber— epoxy composite subject to shock loading

• Published in: Journal of applied physics Vol. 114; no. 22
• Main Authors: Alexander, C. S., Key, C. T., Schumacher, S. C.
• Format: Journal Article
• Language: English
• Published: Melville American Institute of Physics 14.12.2013
• Subjects: Applied physics; Carbon fiber reinforced plastics; Carbon fibers; Carbon-epoxy composites; Dynamic response; Fiber composites; Fiber orientation; Fiber reinforced polymers; Mathematical models; Micromechanics; Porosity; Shock loading
• ISSN: 0021-8979; 1089-7550
• DOI: 10.1063/1.4846116

Unidirectional carbon fiber reinforced epoxy composite samples were tested to determine their response to one dimensional shock loading with the ultimate goal of developing a micromechanics based numerical model of the dynamic response. The material tested had high fiber content (62–68% by volume) and low porosity. Wave speeds for shocks traveling along the carbon fibers are significantly higher than for those traveling transverse to the fibers or through the bulk epoxy. As a result, the dynamic material response is dependent on the relative shock—fiber orientation; a complication that must be captured in the numerical models. Shocks traveling transverse to the fibers show an inelastic response consistent with the material constituent parts. Shocks traveling along the fiber direction travel faster and exhibit both elastic and plastic characteristics over the stress range tested; up to 15 GPa. Results presented detail the anisotropic material response, which is governed by different mechanisms along each of the two principle directions in the composite. Finally, numerical modeling of this response is described in detail and validated against the experimental data.