Fatigue Life Simulation And Prediction System Development For Cold Expanded Holes With Split Sleeve

Since the technique of cold-expanded hole with split sleeve is the most advanced cold-expanded processing in international manufacturing industry of aeronautics and astronautics, and is one of the most effective measures on improving life of fasteners in aircraft structures. So, the cold-expanded hole with split sleeve is simulated by ANSYS to obtain the loading stress field, and simulated by Fatigue to obtain the fatigue life in this paper. Basing BP neural network, the prediction model of fatigue life for cold-expanded hole with split sleeve is also built, and the prediction system is successfully developed by VC++ and MATLAB. All these works are based on the analysis in detail about the technology of the cold-expanded hole with split sleeve processing.The main work and the achievements are as follows:1.The loading stress field of cold-expanded hole with split sleeve is simulated by ANSYS. It is showed that the maximum equivalent stress is located at the open zone of split sleeve. The maximum equivalent stress is about 300 mega Pascal, and the result of analysis is consistent with the reference value.2.Based on orthogonal test,an experimental about influence degree of experimental factors on the loading stress field of cold-expanded hole with split sleeve is studied systematically. And these experiment factors include the value of expanded, the friction coefficient and the sleeve. It is showed that the value of expanded is the most important influencing factor, and the influence of the friction coefficient is minimal, which can be ignored.3.Based on the above result, the fatigue life of cold-expanded hole with split sleeve is simulated by Fatigue. It is showed that the minimum fatigue life of cold-expanded hole with split sleeve is located at the open zone of split sleeve, and the fatigue life increases with the increasing of the value of expanded in a certain range.4.Based on BP neural network, a prediction model of fatigue life for cold-expanded hole with split sleeve is established. The training samples of this model are about 300M super high-strength steel, 30CrMnSiA tempered steel and A3 carbon structural steel. The fatigue life of LY12CZ aluminum alloy is predicted by using of this model, and the predicted result is comparatively ideal. Finally the prediction system of fatigue life is developed by VC + + and MATLAB.