Effect of Testing Mode on Ratcheting and Post-ratcheting Tensile Properties of Annealed OFHC Copper

Abstract

Asymmetric cyclic loading of annealed OFHC copper has been carried out under different stress combinations; bother under engineering and true stress-control mode. It is observed that accumulation of ratcehting deformation occurs rapidly when the tests are carried out under engineering stress-control mode. During true stress-control mode of cyclic loading the number of cycles over which a constant amount of ratcheting deformation occurs exponentially increases with increase of stress ratio at constant maximum stress. The post ratcheting tensile properties show that hardening becomes more in case of prior engineering stress- control tests. Linear variation of post ratcheting tensile properties with stress ratio has been observed in case of true stress-control tests.