Computational Modeling and Optimization of Residual Stress for Large Structural Forgings

In line with Alcoa's goal of manufacturing forgings with consistently low residual stress Alcoa has developed in-house and integrated commercial finite-element tools to model first the heat treatment quench induced residual stress and second the practice of cold work stress relief of large aluminum (alloys 7050 and 7085) aerospace forgings. We will highlight the state-of-the-art tools with examples of how they have been used to improve and optimize quench and cold work stress relief practice. In addition, Alcoa's modeling tools are used to give guidance on the bulk residual stress contribution to machining distortion. We will also acknowledge our validation work that compares measured and modeled residual stress components. Finally, we discuss the limitations of the computational modeling tools and our future direction.