Equivalent CTOD Concept for Correction of CTOD Toughness for Constraint Loss in Steel Weld Components
|Periodical||Materials Science Forum (Volumes 706 - 709)|
|Main Theme||THERMEC 2011|
|Edited by||T. Chandra, M. Ionescu and D. Mantovani|
|Citation||Fumiyoshi Minami, 2012, Materials Science Forum, 706-709, 97|
|Online since||January, 2012|
|Keywords||Brittle Fracture, Constraint Loss, CTOD Fracture Toughness, Failure Assessment Diagram (FAD), Residual Stress, Steel Weld Components, Strength Mismatch, Weibull Stress Criterion|
This paper presents a new fracture assessment method, IST method developed as ISO 27306. The IST method implements an equivalent CTOD ratio, β, for the CTOD toughness correction for constraint loss in structural components. Using β, the standard fracture toughness specimen and structural components are linked at the same level of the Weibull stress. This paper extends the equivalent CTOD concept to weld components. Effects of the weld strength mismatch and residual stress on β are discussed. It is shown on the failure assessment diagram (FAD) that the CTOD toughness correction with β leads to accurate fracture assessments of weld panels, whereas the conventional procedure gives much conservative results.