Modified James-Anderson method for stress intensity factors of three-dimensional cracked bodies

James and Anderson have proposed a method for the determination of stress intensity factors for three dimensional cracked bodies from experimentally-measured two-dimensional fatigue crack growth data. In the present work, the method is improved through the use of 3D fatigue crack closure theory, and it is shown that the modified method can accurately evaluate stress intensity factors for 3D cracks. The explicit procedures given in the paper provide a convenient method for the determination of stress intensity factors for 3D cracked bodies.