ABSTRACT
Many design engineers and other technical people involved in the selection process are accustomed to using published property data, but it is unlikely that many of them have devoted much thought to how the data are obtained, and in some cases, how to interpret them. During the first part of the pulling process, both the tensile stress and the tensile strain continue to increase, and in proportion. In dealing with plastics, creep is important, since it takes place even at room temperature or below. In the design of plastic parts that are intended to support a load over a long period of time, creep should always be considered one of the important design variables. The test procedure includes a discussion of fatigue testing, and specifically points out that it is a research-type test. Basically, two electrodes are applied at specific locations on a test sample; and high voltage at low current is carefully applied until some kind of failure occurs.
