Experimental analysis of the multiaxial failure stress locus of commercially pure titanium at low and high rates of strain

The mechanical response and failure mechanism of commercially pure titanium subjected to combined tension-torsion loading are studied experimentally at strain rates ranging from 10?3 s?1 103 s?1. A novel split Hopkinson bar (TTHB) equipped with a high speed camera was utilised during high-rate experiments, while quasi-static tests were conducted using universal screw-driven machine. multiaxial dynamic experiments demonstrate the ability developed TTHB apparatus achieve synchronisation longitudinal torsional waves upon specimen, satisfy equilibrium specimen attain constant rate loading. envelope analysed over wide range stress states including torsion, shear-dominated tension-shear, tension-dominated plain tension. analyses paths show that these nearly proportional in terms strain. locus constructed normal versus shear space low Drucker-Prager criterion employed approximate assess its sensitivity. dependence reported for first time. allows definition aerospace materials directly and, therefore, evaluation existing failure/yielding criteria.