Mechanical and Thermal Characterization of Unidirectional Aramid/Epoxy

摘要

The results of an extensive experimental investigation of the mechanical and thermal response of an aramid/epoxy unidirectional composite are presented. The three test methods used are the off-axis tension test, the Iosipescu shear test and the off-axis compression test. All test were carried out at room temperature under monotonic and quasi-cyclic loading conditions. Four different off-axis orientations were employed for the off-axis tension and compression tests to determine the initial elastic response and subsequent nonlinear response. The experimental tensile moduli were subsequently compared to the predictions of transformation theory; compressive moduli were compared to finite element analysis. Three different Iosipescu specimens were employed to determine the shear response: specimens with fibers parallel and perpendicular to the longitudinal axis lying in the plane of the specimen and specimens with fibers normal to the plane of the specimen. Thermal expansion coefficients were obtained in the temperature range -50 degrees to +200 degrees F using bonded strain-gage techniques. The results are summarized in tables and stress-strain diagrams.