| Popis: |
Helicopter guide rail fixed parts are an important part of the helicopter refit package. Taking a certain type of helicopter as an example, the flight state which has significant influence on the guide rail fixing parts is selected, and the load is calculated and analyzed by referring to the accumulated empirical load of similar models, and the load spectrum is obtained. The effective stress concentration coefficient is calculated based on the finite element method, the size coefficient is calculated based on the stress field strength method, and the fatigue strength reduction factor is calculated based on the above parameters, surface machining coefficient and load coefficient, and then the S-N curve of the structure of the guide rail fixed parts is obtained. Based on the load spectrum and s-n curve of the structure, the linear Palmgren-Miner cumulative damage model was used to calculate the fatigue life, and the preliminary results were obtained. Using the topological optimization theory of variable density method, the structural optimization model is obtained. The fatigue life of the optimized model is calculated and compared with the preliminary results. The results show that the lightweight design is realized after the optimization, the weight is reduced by 0.3kg, the weight is reduced by 20%, and the fatigue life is increased by 5.1 times. |
