Fatigue Analysis And Structure Optimization Of Heavy-duty Universal Couplling’s Cross Shaft

Fatigue analysis and structure optimization of heavy-duty universalcouplling’s cross shaft are researched in this dissertation. These theories areapplied such as the kinetic theory, the fatigue strength theory and the fracturemechanics theory. Moreover, CAE technology, fracture analysis and orthogonaltest are also used.Main works of this dissertation are as follows.(1) The MSC.Patran and MSC.Nastran are used to the nonlinear staticanalysis of the joint components. The stress distributions of the related parts areobtained. The max equivalent stress at the circular transition of the cross shaft is693MPa. The cross shaft fatigue damage will be happen according to theanalysis results. It is necessary to research the cross shaft’s fatigue life.(2) The CAE technology is used in the modal analysis of the cross shaft. Thecross shaft’s natural frequencies and mode shapes of the first20orders areobtained. The cross shaft’s first6orders are rigid modals. The seventh ordernatural frequency of the cross shaft is1326.7Hz. The covibration will nothappen in the working process of the cross shaft. This suggests that the crossshaft’s structure is reasonable. The cross shaft’s fatigue analysis is based on themodal information of the modal analysis.(3) The MSC.Adams is used to the universal couplling’s rigid-flexiblecoupled modeling and simulation. This work is based on the test data of thecouplling’s actual work condition and the modal neutral file obtained frommodal analysis. These results of stress-time history could be reached from therigid-flexible coupled analysis. The work condition information of the crossshaft’s fatigue analysis is based on those load spectrums.(4) The invalidation analysis technology is applied to the fractured crossshaft’s fracture analysis and metallographic analysis. The relationship betweenthe cross shaft’s fracture and fatigue is further researched. Combing with thenominal stress method, the cross shaft’s fatigue life is analyzed by MSC.Fatiguesoftware. Besides, the shaft’s modal information and work condition informationalso be used to the analysis. The shaft’s life of the forecast is highly similar tothe designed life. According to the orthogonal experimental design, the keyparameters of the shaft are carried on local optimization. The max equivalent stress of the cross shaft is reduced by8.4%compare with original design. Theendurance life of the shaft is increased by9.7%after the optimization.