The mechanical response of commercially pure copper under multiaxial loading at low and high strain rates

In this paper, we present the dynamic response of commercially pure copper subjected to combined tension-torsion loads representative real case impact scenarios. Experiments were conducted both quasi statically, at a strain rate equal 10?3 s?1, and dynamically rates in region between 500 s?1 1000 s?1. All high experiments using novel Split Hopkinson Tension-Torsion Bar instrumented with high-speed photographic equipment. The loading demonstrate capability apparatus generate longitudinal torsional stress waves which are synchronised upon specimen. presented data show that equilibrium conditions nearly steady achieved during experiments. Additionally, analyses paths proportional was attained testing. measured experimental results illustrate, for first time, failure locus material over wide range states including torsion, shear-dominated tension-shear, tension-dominated tension-shear plain tension. quasi-static envelopes herein normal vs shear space motivate development accurate effective constitutive models. To conclude, Drucker-Prager criterion employed approximate loci assess sensitivity material. A moderate asymmetry uniaxial ultimate stresses tension compression is predicted rates.