Contact Finite Element Analysis Of High-Speed Gear In Aero-Engine

In this thesis, the high-speed spur gear of aero-engine accessories is the research object. Static and dynamic contact analysis of gear pair are implemented using finite element analysis software ANSYS and considering the effects of friction on the tooth meshing. Then modal analysis of gear pair is carried out and a solid foundation is laid for dynamic characteristics of the system.The parametric design of involutes spur gear is realized with secondary development tool UG/Open. The method is realized by using Grip to program, using MenuScript to Create a Customized menu, using Visual C++ Calling API function to establish the applications framework. The system generates gear model automatically in line with the user requirements after entering the basic parameters of gear in the dialog box, therefore, it improves the efficiency of the design effectively.By the excellent data exchange interface between UG and ANSYS, the meshing gear is imported into ANSYS and then is transferred into finite element model by meshing. Static contact analysis is executed taking friction into account by using the full Newton-Raphson iterative algorithm and the results are compared with the ones which are calculated by Hetrz contact theory. The results show that the finite element method is more accurate.Dynamic contact analysis of gear pair is executed using multi-body dynamic analysis methods to define rigid body and rotation unit. The trends in contact stress are compared at different speeds. The results show that meshing impact is generated when the teeth mesh into and out, the meshing impact increases with the increase in speed, but also a greater impact on the system is generated when the teeth mesh into.Modal analysis of gear pair is carried out using the Block Lanczos to extract the system's low-order natural frequency and vibration mode. In order to avoid resonance, the frequency of exciting force should be staggered with the system's natural frequency.