Relaxation of a Rectangular Beam and Circular Shaft

The paper provides exact and approximate solutions to the title problems. Time-hardening creep is adopted and the stress dependence is assumed to follow the exponential expression proposed by Soderberg. Even though the exact solutions are easy to work with, some approximate solutions are discussed. These approximate solutions are obtained from the exact ones by simply ignoring certain terms; errors bounds are then directly available.

The exact and approximate solutions are applied to specific problems and compared with the predictions following the exact, numerical or approximate solution of Norton's power law.