J^* INTEGRAL OF THE DEVIATOR STRAIN ENERGY PER UNIT VOLUME AND ITS APPLICATION

J^* integral of the deviator strain energy per unit volume is introduced in this paper. The problem of plane-crack critical growth is discussed and a path-independent line integral J^* is given. Mode I stress intensity factors of cracked beams are obtained using the approach. The results are shown to agree well with those available in the open literature.