Simultaneous Stress Relaxation in Tension and Creep in Torsion of 2618 Aluminum at Elevated Temperature

Experiments are reported for stress relaxation and simultaneous stress relaxation and creep with proportional and nonproportional loading and unloading. Results were compared with predictions of a viscous-viscoelastic theory, and modifications, and strain hardening. Predictions were calculated from results of combined constant-stress tension and torsion creep and recovery tests only, which were reported previously. Results showed that a modified viscous-viscoelastic theory predicted all the observed features and predicted the creep and relaxation rates reasonably well.