Abstract
Current methods for determining fracture toughness values for structures containing weldments rely on homogeneous models. This research invalidates this assumption by using finite element analysis results to calculate applied J values for structures containing a/W--O.l and a/W--O.5 fillet weld toe cracks. The Anderson-Dodds scaling model is applied to quantify the effects of finite size on J contour integral values for structures containing a/W=O.l and a/W=0.5 fillet weld toe cracks loaded in bending and in tension. The negligible effect of material mismatch for the aforementioned structures containing 20% overmatched weldments (weld material stronger than parent material), and 20% undermatched (parent material stronger than weld material) weldments is also shown via application of the AndersonDodds scaling model. The Anderson-Dodds scaling model relies on the assumption that a constant scaling parameter exists between the finite body and infinite body J contour integral values. Hence, as this assumption breaks down the Anderson-Dodds scaling model becomes invalid. This study shows that the Anderson-Dodds can be applied to most of the non-symmetric geometries analyzed without significant error, but that a symmetry causes it to break down for the case of a structure containing and a/W=O.l fillet weld toe crack loaded in tension.
Neligon, Melinda T (1995). Contstraint effects of shallow cracks in structures containing fillet weld toe cracks. Master's thesis, Texas A&M University. Available electronically from
https : / /hdl .handle .net /1969 .1 /ETD -TAMU -1995 -THESIS -N447.