Abstract
Off-axis deformation behavior of a unidirectional thermoplastic carbon/polyamide composite was examined under monotonic compressive loading condition at different temperatures. From the static compression tests, it was clearly observed that the ultimate strength and Young’s modulus of the unidirectional carbon/polyamide composite under compression depend on off-axis fiber orientation. It was also confirmed that the off-axis strength and Young’s modulus decrease as temperature increases, while an opposite feature was found in the Poisson's ratio. The off-axis behavior was almost orthotropic, and the orthotropic nature in ultimate strength was approximately described by means of the modified Tsai-Hill criterion. The orthotropic nature in Young’s modulus and Poisson's ratio was approximately described by means of the orthotropic elasticity theory. Off-axis nonlinear stress–strain curves were adequately predicted using the Sun-Chen one-parameter plasticity model.
