Fracture Assessment of Notched Bainitic Functionally Graded Steels under Mixed Mode (I + II) Loading

The averaged value of the strain-energy density over a well-defined volume is one of the powerful criteria to assess the static strength of U- and V-notched specimens. This contribution is the first to investigate the effect of notch parameters (notch radius, notch depth and notch opening angle) for fracture assessment of specimens weakened by blunt V-notches made of bainitic functionally graded steels under mixed mode loading (I + II). A numerical method has been used to evaluate the boundary of the control volume, the mean value of the strain-energy density and the critical fracture load. Different values of the notch radius (0.5, 1.0, 1.5 and 2.0 mm), notch depth (5.5, 6.0 and 6.5 mm), notch opening angle (30°, 60° and 90°) and distance of the applied load from the notch bisector line (5 and 10 mm) have been considered. Moreover, this contribution shows that the mean value of the strain-energy density over the control volume can also be accurately determined from a coarse mesh for functionally graded steels.