Level-3 Crack-Tip Opening Displacement (CTOD) Assessment of Welded Wide Plates in Bending—Effect of Overmatching Weld Metal
SourceButt-welded wide plates with semi-elliptical surface cracks along the fusion line were tested in four-point bending. The material was normalized low-carbon microalloyed steel that conformed to offshore specifications. The testing temperature was in the range of -40° to 0°C. The test results were analyzed by the crack-tip opening displacement (CTOD) Level-3 method that compared different assumptions for the reference strain in order to assess the effect of overmatching weld metal. The original Level-3 plane stress model and a proposed plane strain model with a modified definition of effective primary stress were compared. Consistent results were obtained by the latter method. A detailed finite-element method (FEM) model was validated, and results from comprehensive analyses of welded and nonwelded models are presented.