Damage mechanics applied to polymers

The static behaviour of Polystyrene (PS) and High Impact Polystyrene (HIPS) has been investigated using three different damage mechanics models. Although the damage mechanism of these polymers is crazing, their mechanical properties are different. The PS specimens behave in a predominantly elastic manner whereas HIPS displays a large amount of plasticity. A series of uniaxial tensile tests has been carried out to determine the respective damage parameters. The results of the experiments illustrate that anisotropic damage occurs in PS and HIPS, even under uniaxial loading. These results are then used to examine the applicability of three damage models to express the damage.