Effect of Stiffness on Serrated Deformation at Very Low Temperatures Under Constant Loading Rate Conditions and its Computer Simulation

Abstract

Serrated deformation behavior at very low temperatures such as AK has been studied by many researchers. Details of this discontinuous unstable deformation, however, have remained unclarified, especially the deformation behavior under constant loading rate conditions which has been examined by only a few researchers. The objective of the present paper is to investigate the deformation under constant loading rate conditions, especially the effects of stiffness, that is, back-stress due to the constraint of surrounding structures on the rapid discontinuous deformation. The onset stress of the discontinuous deformation was lower under constant loading rate conditions than under constant cross-head velocity conditions. It was shown by computer simulation that the amount of rapid deformation under constant loading rate conditions could be effectively decreased and the onset of the first discontinuous deformation delayed by small back-stress.