Virtual Lecture: AS-09: Adaptive Structures Lecture 4 January 2022 1130 - 1245

The return of commercial supersonic flight requires innovative solutions to be developed that meet noise and efficiency requirements for overland flight. To study such a possibility NASA is supporting a multi-disciplinary team of academic and industrial experts to explore the potential of structurally morphing the outer mold line of a supersonic vehicle. The team is considering recent advances in supersonic computational fluid dynamics, sonic boom propagation prediction tools and new design approaches of embedding high actuation energy density Shape Memory Alloys (SMAs) for in situ morphing, leading to optimal low boom signatures in different atmospheric environments and flight conditions. The presentation will focus on the development of the appropriate high temperature NiTiHf SMAs based on the requirement of reliable repeated actuation up to 100K thermal actuation cycles, under high levels of stress. The thermomechanical constitutive modeling of such alloys, their modeling of low cycle actuation fatigue and failure will be discussed. A unified constitutive modeling approach will be described to capture critical phenomena associated with the unique response of SMAs and the development of predictive tools for the design and reliable operation of phase transforming materials for aerospace applications.