Dear everyone

  If we considerer a 3D fracture stress and strain field as a combination of numerous 2D fields in thickness direction, the J integral at each 2D plane can be obtained according to Rice’s definition (Abaqus and Ansys also include this function). What I concerned is the ratio of J integral at the surface of SEB or CT specimen to that at the mid-plane of the specimen. What factors have influence on the ratio? How to find the quantitive relationship between the factors and the ratio in linear elastic model?