Dynamics Analysis and Optimization of a Simplified Axisymmetric Vectoring Nozzle Rigid Flexible Coupling Mechanical System with Clearance Joints

In practice, due to the problems of tolerance, design defects and materials themselves, clearance at joints and flexible component deformation are inevitable. In order to study the impact of the clearance joints and flexible component on the axisymmetric vectoring nozzle (AVEN) mechanism, the rigid flexible coupling dynamic equation of the simplified AVEN mechanism was established by using the Lagrange multiplier method. Specifically, the flexible components are established based on the absolute node coordinate formulation (ANCF), and the clearance impact force is analysed using the Flores Contact force model and the modified Column friction model obtained from the friction and wear test. The influence of flexible components and clearance joints on the dynamics of AVEN mechanism is analysed through the Poincaré map. The results indicate that the clearance joints and flexibility will make the nonlinear characteristics of the system more obvious, reduce the accuracy and stability of the mechanism's motion, increase the joint reaction force. Finally, by optimizing the component parameters, the driving retardation force caused by clearance and flexibility was reduced.