An Integrated Approach to Manage the Impact of Bulk Residual Stress On the Design-Build-Sustain Process for Primary Aircraft Structure

Integrated product development teams and computational methods have received significant attention in recent years as a means to accelerate new material insertion and reduce cost in the product development cycle.  When combined, they form the basis for the field of Integrated Computational Materials Engineering (ICME), which is held up as an enabler for the community with benefits ranging from material design through component design, manufacturing, and even sustainment.  Alcoa has for many years used ICME as part of the product design process, and during that time, substantial progress has been made towards solving myriad complex technical challenges associated with forged part design.  Recently, under the Metals Affordability Initiative (MAI), the Air Force provided opportunity for stakeholder companies to join forces to develop and validate computational capabilities necessary to integrate bulk residual stress into the design and manufacture of forged, aluminum-alloy, primary aircraft structure.  The presentation discusses advances in residual stress modeling achieved during the last several years, summarizes recent residual stress measurements that are part of the validation plan, and outlines the path forward via the MAI program.  The preliminary results affirm that more than ever, knowledge of residual stress influences on design and manufacturing processes is essential to both assure conservatism and maximize performance.