Reduced-Order Models for a Shallow Curved Beam Under Combined Loading

Future U.S. Air Force vehicles require structures that can withstand extreme combined environments. Examples include vehicles exposed to launch, sustained hypersonic velocities, reentry, and stealthy 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 toward developing reduced-order modeling to address the issue of sonic fatigue. These methods have been demonstrated to be useful for predicting the geometric nonlinear response of aircraft structures to stochastic loading. Recent work also demonstrates that these methods are able to predict the response of planar structures in these combined environments. The present study demonstrates that the implicit condensation reduced-order modeling method can also be extended to curved structures experiencing combined thermal-acoustic loading with changing thermal conditions. Successful displacement and strain comparisons for a curved beam structure are made between results from a commercial finite element code and reduced-order models, using a single random pressure load (162 dB) and varying temperature cases.