Model Order Reduction and Nonlinear Dynamic Analysis of the Folding Fin with Freeplay Nonlinearity

To reduce the model size and improve the efficiency of the dynamic analysis of folding fins, a novel condensation modeling method is proposed in this paper.

The linear degree-of-freedoms (DOFs) of the components of folding fins are truncated via finite element model reduction by using the fixed-interface component mode synthesis method, and the DOFs at the connection interface between the adjacent components are reduced via coordinate condensation. The linear and nonlinear case studies of a folding fin with adjustable connection conditions are conducted to validate the proposed condensation modeling method.

The results obtained by the finite element calculation and experiment measurement of a folding fin with different connection conditions are in good agreement with their counterpart of the condensation model, and the computation time of the condensation model is significantly less than that of the finite element model.

The proposed condensation modeling method can significantly improve the computational efficiency and simultaneously guarantee the accuracy compared to the traditional finite element modeling method for folding fins.