Effects of Nonlinear Stress-Strain Rate Relation on Deformation and Fracture of Materials in Creep Range

Fundamental and practical investigations on high-temperature strength of materials have made significant contributions to industrial development for the last twenty-five years. However, an additional effort is required to make clear the effects of dominant factors on the deformation and fracture of materials, since the knowledge obtained to date are not enough to explain the overall phenomena of high temperature strength. In this paper the importance of the effects of nonlinearlity and time-dependence of stress-strain relation on the well-known creep behaviors are reviewed and reexamined on the basis of our laboratory study conducted over the last twenty years.