This paper focuses on the development of nonlinear reduced order modeling techniques for the prediction of the response of complex structures exhibiting “large” deformations, i.e. a geometrically nonlinear behavior, and modeled within a commercial finite element code. The present investigation builds on a general methodology successfully validated in recent years on simpler beam and plate structures by:
(i) developing a novel identification strategy of the reduced order model parameters that enables the consideration of the large number of modes (> 50 say) that would be needed for complex structures, and
(ii) extending an automatic strategy for the selection of the basis functions used to represent accurately the displacement field.
The above novel developments are successfully validated on the nonlinear static response of a 9-bay panel structure modeled with 96,000 degrees of freedom within Nastran.
The application of reduced order modeling (ROM) techniques to hypersonic structures has gained significant momentum in recent years owing to its ability to deliver accurate structural-thermal response predictions with reduced computational costs relative to full order methods. Accurate response prediction is dependent on the selection of an appropriate basis which is relatively straightforward for single discipline problems. For structural problems, the basis is comprised of the natural mode shapes of the structure and duals, which are modes constructed to capture the nonlinear membrane stretching effect. Similarly, eigenvectors of the generalized conductance-capacitance eigenvalue problem have been shown to provide an adequate basis for thermal ROMs. Selecting a basis for multidisciplinary problems may be significantly more difficult because of the unexpected behavior that may result from the interactions between the disciplines. It is proposed here that reduced order models first be developed as above on single discipline arguments, then be adapted, specifically their bases, to account for the interaction as the computations proceed. An adaptive model is most likely needed for the thermal problem, since the corresponding eigenvalues are more densely clustered than for the structural problem, resulting in significant contributions from more modes as the thermal loading conditions change. To investigate these concepts, a representative hypersonic panel is considered here and a thermal reduced order model of it is first developed and validated under single discipline conditions. The applicability of this basis to represent the temperature distribution resulting from a fully coupled aero-thermo-structural interaction is then assessed and a methodology to adapt the thermal basis is proposed and discussed.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.