The Shear Strain to Fracture Characteristics of a Titanium Alloy and an Ultrahigh Molecular Weight Polyethylene Under Complex Loading Conditions

Thin-walled tubular specimens of titanium alloy and an ultrahigh molecular weight polyethylene are twisted at various strain rates up to approximately 100/s with the simultaneous application of an axial tensile load or compressive load. The strain to fracture of the titanium alloy, that is, the point of instability, is calculated and shown to decrease with an increase in the strain rate. It is also shown to decrease with increasing tensile load and increase with increasing compressive load at all the strain rates. The polyethylene also shows a decrease in strain to fracture with an increase in the strain rate but appears to be independent of axial load.