Stationary Creep Stresses for Elliptical Cross-Sectional Pipe Bends Subject to In-Plane Bending

A theoretical analysis is presented which allows the determination of the stationary creep stresses acting in a smooth curved pipe of initially elliptical cross section when subject to in-plane bending. The bend is assumed to be of constant thickness and “thin” compared with its cross-sectional axes. The analysis is based on an energy approach and uses a simple power-type creep constitutive law. Results are presented in nondimensional fashion in terms of the maximum linear elastic beam bending stress in a straight tube. A large range of possible geometries is covered.