A novel hysteresis test for studying crazing and shear yielding in rubber‐toughened polymers

Tensile, tensile impact, compact tension, and fatigue tests were carried out on ABS (acrylonitrile‐butadiene‐styrene), HIPS (high impact polystyrene), and toughened PMMA (poly(methyl methacrylate)). Dumbbell specimens machined from test pieces were then subjected to sinusoidal tension‐compression cycling at low stress amplitudes. The HIPS specimens produced asymmetrical hysteresis loops characteristic of multiple crazing, whereas PMMA gave more symmetrical, regularly shaped, loops. The behavior of the ABS polymers varied with loading history. It was concluded that the hysteresis test provides a useful additional technique for studying deformation mechanisms, especially under conditions that do not readily permit volumetric measurements.