Abstract: A method for making a reinforced pipeline comprising determining the thicknesses of a metallic liner and a reinforcement which are effective to limit stresses on a reinforced pipeline at a known operating pressure to a known percentage of the specified minimum yield strength and a known percentage of at least one actual yield strength along the length of the pipeline which differs from the specified minimum yield strength. Preferably, the reinforced pipeline is pressurized to produce yielding which results in a residual stress pattern effective to resist ductile fracture propagation along a longitudinal axis of said metallic liner along a length of the pipeline comprising at least two actual yield strengths.

Abstract: A method of predicting rupture failure for corroded transmission pipelines uses a model that accounts for the effects of residual and thermal stresses, and settlement of the pipe following installation. The pressure required for failure under a fixed bending moment is different from the pressure required wherein the same bending moment is produced by the settlement of the pipe because the bending compliance increases with plastic straining. The failure criterion depends upon whether or not the hoop strain exceeds the difference between the ultimate hoop strain limit of the material and the remaining hoop strain capacity needed for the material to shed the axial stresses due to bending.