Creep Mechanics
de Josef Betten
In this book constitutive equations for the secondary and tertiary creep stage of anisotropic materials are formulated. To investigate the secondary creep behaviour the existence of a creep potential is presumed. It is established, that regarding to the theory of representation for tensor functions the creep potential hypothesis furnishes only restricted forms of constitutive equations even if a general creep potential is assumed in the anisotropic case. The creep process in its tertiary phase is characterized by a damage tensor. Some possible representations of constitutive equations involving (initial) anisotropy of the material (e.g. from rolling) and anisotropic creep-damage are discussed. The formulation of such equations is based upon theorems regarding tensor-valued tensor functions.
