Summary
While recent designs demand structures more prone to geometric nonlinearity, frictional contact can occur in the interaction between adjacent components. The accuracy and efficiency of the Rubin model order reduction technique enhanced with static modal derivatives are investigated for the vibration analysis of geometrically nonlinear structures with friction contact. This reduced model facilitates the contact treatment by keeping the contact degrees of freedom in generalized coordinates while simulates geometrically nonlinear behavior due to the addition of the static modal derivatives to the reduction basis. The effectiveness of this method is studied by the vibration analysis of a cantilever beam under these nonlinearities. Rubin with free interface modes and their static derivatives is also compared with Craig-Bampton method with fixed interface modes and their static derivatives. The results highlight the good performance of the Enhanced Rubin method. In other words, accurate results are achieved by a small number of modes in the reduced space which leads to low online computation time. Furthermore, the analysis demonstrates the considerable impact of a geometrically nonlinear model on the accurate prediction of contact states.
