Relationship between J-integral and averaged strain-energy density for U-notches in the case of large control volume under Mode I loading

The main purpose of this technical note is to present a relationship between J  -integral and averaged strain-energy density (W¯) in U-notches under Mode I loading for brittle or quasi-brittle materials. In this work, control volume includes the rectilinear edge of the notch in addition to semi-circular arc of the notch root. A dimensionless function (f) between J   and W¯ has been presented in this paper. Finite element analysis has been used for verification. It is found that this relationship is identical for tension or bending loading.