Study on the Dynamic Modeling for Free Beam Structure Based on Parameter Identification

To improve the tank aiming accuracy, this paper studies on the nonlinear vibration characteristics caused by the clearance between the barrel and lining. Based on the parameter identification, a free beam modeling method with clearance is proposed. Firstly, based on the Hamilton principle and hypothesis mode method, the free beam dynamic model framework with clearance is established. Secondly, the clearance time-varying stiffness and damping are obtained by the wavelet identification method from experimental data. Hence, the clearance dynamic model is established to describe the nonlinear dynamic behavior accurately. Finally, based on the similarity theory, the scaled model is used to verify the modeling method effectiveness by evaluating the frequency response function (FRF) error between the proposed model and test model. The results show that the FRF relative error is less than 2% between the measured and simulated value based on time-varying parameters, the coincidence index is more than 85%, under the 95% confidence index. It is proved that the dynamic modeling method could improve the barrel-lining dynamic model accuracy effectively with the clearance factor.