THE DETERMINATION AND APPLICABILITY OF COD (CRACK OPENING DISPLACEMENT) TEST DATA

The continuity exhibited between the linear elastic and general yielding fracture mechanics approaches has led to the adoption of a unified procedure for fracture toughness testing, in which respectively the applied force at fracture is determined and the K sub Ic calculated, or the crack tip COD is derived from clip gauge displacement measurements, using an experimental calibration procedure. Experimental results are presented to illustrate the limits to which the COD approach is confined, in an attempt to define the areas where COD can be unambiguously used. Direct photographic records of the notch profile, during loading, facilitate measurement of the effective COD at any location along the crack length, while the use of an electrical potential technique indicates the onset and extent of macroscopic fibrous crack extension. The practical implications of these results are discussed both with respect to the current definition of COD, and in terms of defect significance. (Author)

• Corporate Authors:

  British Iron and Steel Research Association

  24 Buckingham Gate
  London SW1,   England 
• Authors:
  • ELLIOTT, D
  • Walker, E F
  • May, M J
• Publication Date: 1971-6

Media Info

• Pagination: 15 p.
• Serial:
  • BISRA Open Report
  • Publisher: British Iron and Steel Research Association

Subject/Index Terms

• TRT Terms: Cracking; Fracture mechanics; Measurement; Stresses
• Uncontrolled Terms: Crack propagation; Stress intensity factors
• Old TRIS Terms: Crack opening measurement
• Subject Areas: Marine Transportation; Materials;

Filing Info

• Accession Number: 00024775
• Record Type: Publication
• Source Agency: National Technical Information Service
• Report/Paper Numbers: MG/S/7/71
• Files: TRIS
• Created Date: Jan 14 1974 12:00AM