An investigation of crack blunting processes under plane strain conditions

The process of crack blunting was investigated in the present work using direct observations in the scanning electron microscope (SEM). It was found that there are two deformation processes at the crack tip which lead to crack blunting. Shear deformation results in a square crack tip and is characteristic of the plane stress condition at the surface whereas plane strain deformation results in a rounded crack tip. It was noted that the crack …