There has been much work reported recently dealing with failure in polymeric materials. Many of the studies used prenotched samples to study either time dependent crack propagation under deal load or crack propagaton under cyclic loading. These studies provide information about the crack propagation process in polymers. However, their usefulness in predicting material failure is limited due to the fact that, in many polymers, crack propagation accounts for only a small portion of the material lifetime. In the reported work it has been assumed that a phenomenological approach, which implicity includes various aspects of failure, provides a better framework for studying failure than examining only one of the processes individually. This is particularly so when one considers the difficulty of studying crack initiation. It is shown that failure is the result of a cumulative damage process. When the damage reaches a critical value, then failure occurs. If the rate of damage accumulation is a function of only the current stress and not of stress rate or of the current state of damage, the simplest form of this concept is valid. This is the linear additivity of damage law. this contribution examines how well the failure and fatigue of poly(methyl methacrylate (PMMA) are descirbed by this law.
|Number of pages||9|
|Journal||ACS Symposium Series|
|State||Published - 1978|
|Event||Durability of Macromol Mater, from a Symp at the Meet of the ACS, 176th - Miami, FL, USA|
Duration: Sep 11 1978 → Sep 14 1978