Fracture Mechanics Applied to Elevated Temperature Crack Growth

Abstract

Twenty-six isothermal crack growth tests were performed on Hastelloy-X tubular specimens at a variety of temperatures and strain ranges. Conditions were selected to include nominally elastic and nominally plastic conditions. A number of parameters including the stress intensity factor, strain intensity factor, J-integral, Crack Opening Displacement, and Tompkins model were examined for their ability to correlate the data. Test conditions were selected such that growth rates at a single value of the parameter were obtained at radically different crack lengths, thus exploring the geometry independence of the correlating parameter. None of the parameters were fully satisfactory. However, COD calculated from J-integral appeared to be the most successful.