New Methodologies for Efficient and Accurate Fatigue Prediction of Seam Welds 2013-01-1008
The fatigue behavior of many structures, e.g. chassis components, or frame structures, often is restricted by the fatigue life of their welded joints. The fatigue of welds depends on the stress and strain histories in the toes and roots of the weld. Numerous research projects in the past have shown that knowing these stress histories (notch stresses) allows good fatigue prediction for welds. But the roots and toes are geometrically complex and of course also depending on the real welding process and therefore it efforts a lot of manual modeling to achieve local notch stresses by Finite Element simulation.
Due to this methods have been developed to simplify the modeling effort and evaluate the local stresses and fatigue from the local load situation in the weld joint itself. These methods had been restricted to sheet structures modeled by shell-elements. In thick structures more and more modeling by solid elements is used in practice. In several application sheets are welded to casted structures.
This paper shows a new approach to calculate the notch stresses for arbitrary connections between shells-shells, solids-solids and shells-solids and presents a new technology to automatically include the notch effect in the calculation using Neuber's microscopic structural length.