Inelastic Flexibility and Strain Concentration of Pipe Bends in Creep Range with Plastic Effects

The creep behaviors of pipe bends under in-plane bending are studied by the use of the simplified ring element method. The typical two loading cases are studied; (a) constant in-plane moment, and (b) constant in-plane rotation. The present paper investigates (a) inelastic flexibility, (b) creep strain concentration, and (c) stress relaxation by considering effects of yielding on creep deformations. The numerical results verify the validity of the previous analytical methods for elastic stationary creep behaviors by Spence or Kachanov.