A Method of Analyzing Creep Data
Abstract The authors present a method for studying creep data which has been in use for the past four years at the Aluminum Research Laboratories. It is shown by graphs that a linear relationship exists between the logarithm of the creep and the logarithm of the elapsed time for a given material at ordinary room temperatures and constant stress. This is established by the fact that the logarithmic curves for a given material at a constant temperature have a constant slope for a relatively wide range of stresses. It is pointed out that the relative effect of cold working upon the strength of different metals seems to explain the behavior of the metals when failure is impending, this being indicated by the tendency of the logarithmic creep-time curves to depart from straight lines. The authors conclude that when homologous stresses based on the tensile strength of the material are considered, different materials exhibit very similar characteristics in the relationship between the homologous stress and the logarithm of the time necessary for a given amount of creep to occur.