Cyclic Mechanical and Fatigue Properties for OCTG Materials

Abstract

Much of the design for well structures subjected to high-amplitude cyclic loading is based on material assumptions that extrapolate strength properties from uniaxial, monotonic tests to conditions where cyclic, multiaxial stresses are imposed. The full-length paper presents results from cyclic testing on common oil-country tubular goods (OCTG) materials and shows the difference between physical behavior measured under cyclic-loading conditions and theoretical behavior extrapolated by numerical modeling. Modeling theories for plastic deformation are discussed, including their limitations and relevance in a cyclic-loading environment.