scope:

This Bulletin contains three reports on research work performed at the University of Kansas on CTOD and J-integral test studies of A36 steel. Publication of this Bulletin - WRC Bulletin No. 351 was sponsored by the Subcommittee on Failure Modes of Components of the Pressure Vessel Research Council of the Welding Research Council. In this study, finite element analyses are employed to compare the elastic-plastic behavior of square (cross-section) three-point bend specimens with crack-depth to specimen-width ratios (a/W) ranging between 0.50 and 0.05. The two-dimensional analysis of the specimen with an a/W ratio of 0.15 reveals a fundamental change in the deformation pattern from the deep crack deformation pattern. The plastic zone extends to the free surface behind the crack concurrent with the development of a plastic hinge. For shorter cracks (a/W = 0.10 and 0.05), the plastic zone extends to the free surface behind the crack prior to the development of a plastic hinge. For longer cracks (a/W > 0.20), a plastic hinge develops before the plastic zone extends to the free surface behind the crack.