Description

The course will cover:

  • Background
    • Discussion on flaws in pipelines and the methodology used to estimate the critical loads that flaws propagate
  • Basic concepts
    • Material toughness and crack driving force will be reviewed
    • Current methods for stress-based design to establish critical conditions
      • Crack-tip opening displacement, Failure Assessment Diagrams
    • Discussion on tearing instability
  • Recent developments
    • Developments in strain-based design, introduced primarily for pipelines crossing unstable terrain or subjected to plastic strain during pipe laying, will be discussed.
  • Methodology of ECA: Standard techniques to perform ECA based on fracture mechanics principles are available in a number of pipeline standards, including CSA Z662 (the Canadian pipeline code). For stress-based design, ECA may be done using the Crack Opening Displacement COD design curve (CSA) or Failure Assessment Diagram FAD.
  • Current Developments: To support strain-based design, a toughness testing method using a single-edge-notched tension-loaded SE(T) (or SENT) specimen is nearing standardization