Effect of three-dimensional deformation on the limit load of highly weld strength undermatched specimens under tension

Abstract

In the case of welded structures with cracks, a number of parameters, such as those with units of length, makes it difficult to present the results of numerical solutions in a form convenient for direct engineering applications, such as flaw assessment procedures. For centre-cracked components under tension, it is shown in the current article that an effect of crack length on the limit load can be taken into account by means of an upper bound limit load for the corresponding structure with no crack without any additional numerical treatment. Using this result, it is sufficient to find an upper bound limit load for the structure with no crack and then to apply the analytical formulae for finding the corresponding limit load for the structure of interest. Welding of some aluminium alloys for structural applications usually leads to a significantly lower strength (undermatched) weld joint. The approach proposed is used to demonstrate an effect of three-dimensional deformation on an upper bound limit load for such highly strength undermatched centre-cracked welded specimens under tension. This result can also be used in metal-forming applications where upper bound solutions are more useful than lower bound solutions.