Weld Residual Stress and Distortion Analysis of the ARES I-X Upper Stage Simulator (USS)
Volume 6: Materials and Fabrication, Parts A and B
An independent assessment was conducted to determine the critical initial flaw size (CIFS) for the flange-to-skin weld in the Ares I-X Upper Stage Simulator (USS). The Ares system of space launch vehicles is the US National Aeronautics and Space Administration's plan for replacement of the aging space shuttle. The new Ares space launch system is somewhat of a combination of the space shuttle system and the Saturn launch vehicles used prior to the shuttle. Here, a series of weld analyses are
... ormed to determine the residual stresses in a critical region of the USS. Weld residual stresses both increase constraint and mean stress thereby having an important effect on fatigue and fracture life. While the main focus of this paper is a discussion of the weld modeling procedures and results for the USS, a short summary of the CIFS assessment is provided. SUMMARY This paper discussed the development of weld residual stresses in the Ares I-X space shuttle replacement and the important effect weld residual stresses have on the critical initial flaw size. It is clear that careful design of weld fabrication procedures, including joint type, weld parameters, weld sequence, fabrication constraints, and distortions are very important to improve the life of welded fabrications.