Dynamic anisotropic behavior of amorphous polymers

Dynamic anisotropic responses of two amorphous polymers have been determined under high strain-rate uniaxial tension and compression conditions. A split Hopkinson tension bar was modified to determine the dynamic tensile stress-strain behavior from the low-strength and low-mechanical-impedance specimens. An aluminum split Hopkinson pressure bar was used to determine the dynamic compressive responses. Pulse shaping was applied to ensure homogeneous deformation in the low-impedance specimens. Compared to quasi-static behavior, dynamic tension causes stiffer stress-strain behavior during loading, whereas dynamic compression results in significantly higher compressive strengths.