Basics of Finite Element Applications to Pipelines

The use of finite element analyses (FEA) is widespread in pipeline engineering practice, in particular for major hazard industries such as oil and gas. It allows a comprehensive understanding of the loadings and resistances at each specific region, and a sounder measure of the safety margins against each of the relevant failure modes. As such, high levels of operational safety can be maintained while minimizing conservatism and unnecessary costs. Pipeline engineers make use of a wide range of analysis types, following different codes and standards. These typically include flexibility analyses; pipe-soil interaction; local instability; damaged condition assessments (cracks, corrosion, erosion, etc.); and risk analyses. Preoperational analyses are also required in some cases, to assess manufacturing (bending, welding) or installation (subsea pipelaying) processes. This chapter intends to support pipeline engineers in making use of systematic, effective, and meaningful FEA. It starts with a brief presentation of the method. It then covers the three main steps of any analysis, namely, modeling and preprocessing; the numerical simulation itself; and postprocessing and assessing results. For each of these, key aspects and good practice are discussed, making use of examples that are relevant to pipeline engineers.