Fatigue Life Improvement of Threaded Pipe Couplings

In this study it is demonstrated experimentally that the fatigue life of threaded pipe couplings can be improved by providing a more uniform load distribution over the threads of the coupling. The load distribution was changed by applying both global and local stiffness reductions to the coupling. The obtained results were evaluated using finite element simulations of 2D axisymmetric models. To study the validity of these models a critical comparison was made with a full 3D model that accounts for non-linearities in material and contact properties.