Modeling Impact and Mechanical Response of Carbon-fiber Reinforced Polymer Composites

摘要

Carbon fiber-reinforced composites typically do not perform as well as materialscontaining polymer and glass fibers in ballistic impact applications. This is due to thebrittle nature of the carbon fibers, which cannot admit the larger deflections required forcomposite- and fabric-based armors to stop a projectile without breaking. That said, thehigh stiffness and strength and low density of carbon fiber composites makes them idealfor use in structural regions of vehicles, aircraft, and other assemblies that may beunintentionally subjected to high-rate impacts while in service. Thus, an understandingof the damage mechanisms active in carbon fiber composites during impact and howthey differ from those that occur in polymer and glass fiber composites under similarconditions is of interest to anyone performing impact modeling of these materials. Testsof carbon fiber composites with two-dimensional non-crimp and three-dimensionalwoven architectures were devised in order to improve the understanding and modelingof these materials under impact conditions. Carbon fiber composite panels weresubjected to ballistic impact to obtain both residual velocities of the projectiles andbackface deflection measurements. Additionally, slow-rate mechanical tests of thecomposite were conducted to provide information about the material’s response undervarious stress states. Mesoscale models of the two- and three-dimensional compositeswere constructed. These models include individual elements for the carbon fiber tows,resin matrix, and interfaces between the two constituents. Results from the finite elementcomputations were compared to both the ballistic impact and mechanical test data.