Fracture of semi-brittle U-Ti polycrystals -- shielding model extension to a lower crystal symmetry

In U-Ti alloys, a simplified dislocation shielding model might represent the lower shelf regime of fracture toughness as a function of microstructure, temperature and strain rate. This proposed shielding model centers on the local back-stress for shielding and, as such, depends on the friction stress and its strain rate sensitivity. Shielding concepts might be applicable to some brittle lower symmetry crystal structures obeying similar trends typical to thermally activated deformation mechanisms