ACTA AERONAUTICAET ASTRONAUTICA SINICA ›› 2020, Vol. 41 ›› Issue (5): 223507-223507.

• Solid Mechanics and Vehicle Conceptual Design •

### Dynamic characteristic analysis for a folding fin with freeplay nonlinearities based on mode synthesis method

WANG Qiang1,2, MA Zhisai1,2, ZHANG Xin3, LIU Yan3, DING Qian1,2

1. 1. School of Mechanical Engineering, Tianjin University, Tianjin 300350, China;
2. Tianjin Key Laboratory of Nonlinear Dynamics and Control, Tianjin 300350, China;
3. Beijing Institute of Electronic System Engineering, Beijing 100854, China
• Received:2019-09-18 Revised:2019-10-08 Online:2020-05-15 Published:2019-10-24
• Supported by:
National Natural Science Foundation of China (11802201,51575378,11972245); China Postdoctoral Science Foundation (2017M621075)

Abstract: Nonlinear dynamic characteristics of a folding fin with freeplay nonlinearities are analyzed based on the mode synthesis method. Firstly, the finite element model with hinge connection is established according to the structural characteristics of the folding fin, and subsequently reduced by using the free-interface mode synthesis method. Secondly, sweeping and modal tests are carried out on the folding fin without freeplay nonlinearities to test the accuracy of the finite element model and its reduced substructure model, and the equivalent linear joint stiffness of the hinge is obtained based on the model updating. Finally, the equivalent linear joint stiffness and the freeplay value are combined to obtain the nonlinear joint stiffness of the hinge under different freeplay, and the nonlinear dynamic model of the folding fin with freeplay nonlinearities is established. Numerical simulation of the folding fin with freeplay nonlinearities is carried out based on the nonlinear dynamic model, and the calculated results are in good agreement with their experimental counterparts, which further demonstrate the accuracy of the established nonlinear dynamic model and its feasibility in the analysis of nonlinear dynamic characteristics of folding fins.

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