On Fracture Criterion of Titanium Alloy under Dynamic Loading Conditions

One of the most important factors in ensuring the adequacy of the mathematical modeling of limiting states of structures is the choice of the material local fracture criterion and accurate determination of its parameters. The paper discusses some traditional approaches to the construction of local failure criteria of metals under dynamic loading, methods of their parameters identification, as well as the development of these approaches on the example of impact penetration problem. The work focuses on the possibility of modeling viscous and brittle types of fracture within a single deformation type criterion, while the dependence of fracture strain on the stress triaxiality ratio can became complicated and nonmonotonic. The quality of the considered criteria is determined by comparing the results of virtual simulation with the data of full-scale experiments that implement various types of stress state and failure mechanisms. The results of full-scale and virtual compression, tension and penetration dynamic tests of the titanium alloy samples are given. Virtual experiments were conducted using nonlinear LS-DYNA® code.