Z. Yang, H. W. Ludwig, Caterpillar, Inc., Peoria, IL

Summary: The primary goal of this research is to increase welded-joint fatigue life and to reduce energy use through product performance and productivity improvements using an integrated modeling approach. The fatigue strength of welded-joint is currently the bottleneck to design high performance and lightweight welded structures using advanced materials such as high strength steels. In order to achieve a high fatigue resistant welded-joint it is necessary to manage the weld bead shape for maximum fatigue strength, produce preferable residual stress distribution, and obtain the desired microstructure for improved material toughness and strength. This is a systems challenge that requires the relation of various welding process parameters and material chemical compositions to the weld bead shape, microstructure, property, residual stress and final fatigue performance.