THE STRESS INTENSITY FACTOR OF CYLINDRICAL CRACKS

An analytical expression for the stress intensity factor K1 of a cylin drical crack situated at a fiber-matrix interface has been developed. A model of the crack as a pile-up of Somigliana ring dislocations is r eplaced by an equivalent pair of superdislocations which leads to the analytical solution. The interaction between these two dislocations pr ovides a closed form expression for the J-integral for the cylindrical crack and thus for the K1 stress-intensity factor. The resulting clos ed form expression for K1 is very close to the true value when the rad ius of the crack is less than the crack length.