Design Sensitivities of Response/Fatigue Life of Panels to Thermo-Acoustic Loads

Among the critical components of the next generation launch technology (NGLT) is the design of panels and ?integrated panel systems? (panel + support + thermal protection system). Such an effort can be built upon ELSTEP/FAT, an existing ZONA software providing accurate predictions of the response and fatigue life of panels subjected to severe acoustic loads and thermal effects. The work carried out successfully during the Phase I led to the formulation and proof-of-concept validation of an estimation strategy of the sensitivities of a panel to changes in its geometric and/or material properties. Accordingly, the first focus of the proposed Phase II effort will be on the generalization of the approach to account for changes in all aspects of the 2 or 3-dimensional panel geometry and on the various material properties involved (Young?s modulus, ply angles and thickness, ...). Panels are not independent structures but are part of more complex systems, e.g. panel + support + TPS, and an accurate estimate of the response/life of the panels must include the interaction with these other components. Accordingly, the predictive and sensitivity capabilities of ELSTEP/FAT must be extended and validated for such integrated systems. Computational aspects will also be re-visited to maintain the efficiency of ELSTEP/FAT.