Finite Element Modeling And Analysis Of Antenna Turntable Bearing-gear System

The turntable of a gantry radar antenna is a complicated bearing-gear system including three rotational motions, that is horizontal rolling, pitching and azimuth. Because of Bearing-Gear system is coupling of different vibration, and the form of the vibration is very complex. stiffness of the system is changed by time, contacted impact and error of manufacture and setting, which have a great influence to the structure, so it is hard to get accurately analytic result only by theory analyse. In this paper, static stiffness and strength analysis, modal analysis and dynamic analysis of the system are performed using finite element method(FEM). The main contents are included as follows:①Based on the basal principle of finite element mesh partition, quadrilateral shell element, hexahedral element, wedgy element, rigid element and spring-damper element are employed to build the finite element model in Hypermesh software.②Via middle file, the model is imported into ABAQUS software for static analysis. One gravity is loaded on the model in three coordinate axis directions respectively and three bolts are fixed. Stress distribution contour and displacement distribution contour of three operating conditions are obtained.③Connection elements and spring-dashpot elements are applied to simulate bearing connection and gear mesh respectively. Research on the equivalent average stiffness and damping of the bearings and tooth contact is carried out. The model is calculated in the ABAQUS software. And the results show that the first three-order modes of vibration are accord with the experimental data.④In the bearing-gear system, half of sine wave whose swing is 15 gravities impact acceleration is imposed on the three bolts along the X axis, Y axis, Z axis direction respectively, Dynamic stress distribution and regulation changing with time under the impact loading of the system are derived.⑤Through the above analysis, the larger stress and deformation regions of the structure are found, and some suggestions on how to improve stiffness and strength are put forward.