Evaluation of the intrinsic crack growth rates of weld joints

A method is presented for evaluating the intrinsic fatigue crack growth rate (FCGR) by excluding the effect of welding-induced residual stresses. Calculation procedures have been developed and demonstrated via an example of crack growth across a longitudinal weld subjected to constant amplitude loads and also constant applied stress intensity factor ranges. Trends of intrinsic FCGR in different weld regions are identified. The methodology should also be applicable for crack propagation within and parallel to a weld for establishing intrinsic FCGR laws.