Proposal of limit moment equation applicable to planar/non-planar flaw in wall thinned pipes under bending

In this paper, limit bending moment equation applicable to all types of planar and non-planar flaw in wall thinned straight pipes under bending was proposed. An idea to rationally classify planar/non-planar flaw in wall thinned pipes was proposed, based on the experimental observation focused on the fracture mode. The results point out the importance to distinguish axially and circumferentially long flaws in wall thinned pipes. (author)