Indirect Reduced-Order Modelling of Non-conservative Non-linear Structures

Engineering structures are often designed using finite element (FE) models. Performing non-linear dynamic analysis on high-fidelity FE models can be prohibitively computationally expensive, due to the very large number of degrees of freedom. Non-linear reduced-order modelling allows the salient dynamics of the FE model to be captured efficiently in a smaller, computationally cheap reduced-order model (ROM). Recent developments in indirect reduced-order modelling techniques enable ROMs to be developed efficiently, accurately, and robustly, for a wide range of structures. Nevertheless, these methods are applicable to conservative systems and are unable to capture the effects of, for example, damping and external forcing. In this work, we show how indirect reduced-order modelling methods can be extended to non-conservative non-linear structures, which offers invaluable insight into the behaviour of the system. We demonstrate the proposed method using a simple oscillator.