The results of linear elastic finite element analyses of stress concentration factor (SCF) and through-thickness stress distribution for 80 weld toe T-butt plate geometries are presented in parametric form for tension (membrane) loading. The closed-form solutions, which describe the stress state of the two-dimensional plane stress models studied in terms of weldment angle, weld toe radius, weld attachment width and plate thickness, are accurate and wide ranging. The SCF is presented in full parametric form and also as a simple reduced expression, quantifying the degree of error from raw data in each case. An expression for the stress distribution through the potential Mode I crack plane of the uncracked geometries is also presented in full parametric form. It is anticipated that these HBC equations will be particularly useful in the calculation of weight functions for stress intensity factors (SIFs) of fatigue cracks emanating from weld toes in T-butt welded joints, especially in the presence of known residual stresses, or those resulting from peening.

This paper reports fracture toughness data on aluminium alloy 6061 reinforced with 15 vol% of Al₂O₃ particulate of average size 13 μm. Composites were cast/extruded and heat-treated to give under-aged, peak-aged and over-aged samples, with both longitudinal (L-S) and transverse (T-S) properties being measured to determine the effects on toughness of the banded structure produced via extrusion. This anisotropy was reflected in the toughness results, primarily in the tearing modulus. Comparisons were made to the behaviour of layered/laminated composites where the effects are more dramatic and designed into the structure. This suggests that greater improvements to the fracture critical properties (at least in one orientation) could be obtained by purposely segregating the reinforcement during casting, then extruding/rolling to create a more segregated composite than that tested presently. The current results are compared with those from other similar composites reported in the literature.