On the Use of Reduced-Order Models for a Shallow Curved Beam Under Combined Loading

Future USAF vehicles require structures that can withstand extreme combined environments. Examples include vehicles exposed to launch, sustained hypersonic velocities, re-entry, and stealth aircraft with buried engines and ducted exhaust. Two of the many conditions that a structure in these environments will experience are elevated temperatures and high acoustic loading. Computational methods are needed to rapidly explore the design space for extreme environment structures. There has been a significant amount of work in the area of reduced-order modeling to address the issue of sonic fatigue. These methods have been demonstrated useful for predicting the geometric nonlinear response of aircraft structures to random, fluctuating pressure loadings. Recent work shows that these methods are sufficient for predicting the response of planar structures in combined thermal-acoustic environments. The present study demonstrates that a reduced-order model can also be extended to curved structures experiencing combined thermal-acoustic loading. Successful displacement and strain comparisons for a curved beam structure are made between results from a commercial finite element package and reduced-order models, using a single random pressure load (162 dB) and varying temperature cases.