In the present study, the nonlinear dynamic model of a deployable missile control fin is established. A deployable missile control fin has some of structural nonlinearities because of a worn or loose hinge and manufacturing tolerance. The structural nonlinearity cannot be eliminated completely and has significant effects on the static and dynamic characteristics of the control fin. Thus, it is important to establish the accurate nonlinear dynamic model of the missile control fin. The deployable missile control fin can be subdivided into two substructures represented by a linear dynamic model and a nonlinear hinge with structural nonlinearities. From dynamic tests, the nonlinear hinge parameters are identified and the nonlinear hinge model is established by using the system identification method like Force-State Mapping Technique. The substructures, which have inaccuracies present in a finite element model, are improved by using Frequency Response Method from modal tests. The substructure models and the nonlinear hinge model should be coupled to establish the nonlinear dynamic model of the fin by using the substructure synthesis like Craig-Bampton method. Finally, the established nonlinear dynamic model of the deployable missile control fin is verified through modal and dynamic tests.
