Experimental characterization of anisotropic tensile mechanical behavior of pure titanium tube

The anisotropic tensile mechanical properties of pure titanium (TA2) tubes were studied by means of theoretical analysis, finite element simulation and tensile tests. Based on the stress analysis of circumferential tensile of TA2 tube, an equation for calculating the tangential force of circumferential tensile specimen was established, and the relationship among tangential force, friction and position of ring specimen was analyzed. The finite element simulation analysis of circumferential tensile process of TA2 ring specimen was carried out, which verified the tangential force equation derived from theoretical analysis. The effect of gauge length and friction on necking and tensile load was analyzed, and the optimal gauge length was selected for the ring hoop tensile test. Finally, the axial and circumferential tensile digital image correlation experiments were carried out to verify the theoretical and finite element simulation results. The friction coefficient between TA2 tube and D-blocks (using Teflon lubricant) was determined by the inverse finite element method and the friction experiment, and the true stress–strain curve of TA2 tube was obtained. The results show that the axial and circumferential mechanical behaviors of TA2 tubes are significantly different and anisotropic.