DAMAGE MECHANICS APPLIED TO ELASTIC PROPERTIES OF POLYMERS

The elastic properties of Polystyrene (PS) and High Impact Polystyrene (HIPS) have been investigated using one-dimensional and two-dimension al damage mechanics models. The damage mechanism of these polymers is crazing. However, their mechanical properties are different. The PS sp ecimens behave in a predominantly elastic manner, whereas HIPS display s a large amount of plasticity. A series of uniaxial tensile tests has been carried out to determine the respective damage parameters and da mage strain energy release rates. The results of the experiments illus trate that anisotropic damage occurs in PS and HIPS, even under uniaxi al loading. The damage strain energy release rate of HIPS is very much higher than that of PS. These results are then used to examine the ap plicability of the damage model to express the damage. The principal d irections of the damage of PS and HIPS are also discussed.