摘要
In order to suppress the low-frequency resonance phenomenon in the engine-servo loop during the development of the 1200 kN LOX/kerosene engine,the inherent characteristics of the loop were analyzed by finite element simulation and experiment.Based on the method of finite element simulation,the modal analysis of the engine-servo loop was carried out,and the finite element model was modified according to the results of modal test,so that the results of finite element simulation were in agreement with the results of the modal test.On this basis,various sensitive factors were analyzed with the finite element software.The results show that the stiffness of the bearing and gimbal mount as well as the stiffness and dip angle of the pull rod have great influence on the natural frequency of the engine.Based on these conclusions,the structure of the engine was improved.The modal analysis of the improved single-engine and double-engine structures was carried out using numerical simulation and modal test.The results show that the low-order frequency of the improved single-engine and double-engine structures was significantly improved,and the effectiveness of the improved scheme was verified,which provides a solution to improve the low-order natural frequency in the engine-servo loop.
