Stress intensity factors and fatigue growth of a surface crack in a drill pipe during rotary drilling operation

Abstract : Drill pipe in a curved section of the drilled well is considered as a rotating hollow cylinder subjected to bending and tension loads. So in this paper, the stress intensity factors and the fatigue growth of a circumferential semi-elliptical surface crack in a hollow cylinder subjected to rotary bending and tension are studied. A stress intensity factor database for three loading cases is build for numerous configurations using 3D Finite Element Models. The crack propagation model employs the Walker fatigue growth rate law. Using this model, we can study the evolution of parameters characterizing the process of crack propagation.