Effect of Hydrostatic Pressure on Fracture Toughness : 2nd Report, Elastic-plastic Fracture Toughness

Abstract

To investigate the effect of hydrostatic pressure on the fracture toughness of boron steel and aluminum alloy, a compact tension test based on ASTM Standard is carried out under pressure up to 400 MPa. The displacement at the crack initiation is detected by an electric potential difference method under pressure. The elastic-plastic fracture toughness J_IC increases with an increasing increasing pressure. The phenomenon of the increase of fracture toughness due to pressure is confirmed by measuring a critical stretch zone width of boron steel. The experimental J_IC values are compared with the J-integral values analyzed by FEM.