Pages: 19 Published: Jan 1983
In the previous chapter a number of creep equations were presented, each describing creep as a function of material and operating conditions. In almost all cases these equations were derived from data obtained from tests in which the operating and material variables were held constant throughout the test. Moreover, many data were from creep tests in which the material was subjected to a single, normal tensile stress σ and the creep deformation measured in the direction of the applied stress. Even in the cases in which biaxial stress conditions existed (for example, pressurized tubes), the creep data were taken as creep strain in one direction (hoop or circumferential direction) as a function of the normal stress in that direction. As a result, the creep equations based on these data predict creep in one direction of a component as a function of the applied stress in that direction and for constant material and test conditions.
Paper ID: STP34414S