In this work, the exact analytical stress intensity factor has been obtained for an elliptical crack embedded in an infinite elastic body and subjected to an arbitrary applied normal stress field (Mode I), including the special case of an applied concentrated force, i.e. the weight function (Greens function) for an elliptical crack. The weight function enables the determination of the stress intensity factor for an elliptical crack, induced by an arbitrary applied normal stress field, by integrating the product of the weight function and the applied stress field over the crack...