Design and finite element analysis of a fatigue life prediction for safe and economical machine shaft

In materials engineers, it is important to determine the cause of failure of a machine component, to prevent prospect occurrences and increase the performance of the component structure. In this study, the parameters of the fatigue life of machine shafts are investigated. An analysis of the nut cracking machine shaft was conceded for plastic deformations. The optimum safe and economical design of a machine shaft was proposed. The 3D model of a shaft was produced with Inventor® using absolute coordinate. The results of the commercial finite element analysis (FEA) and calculations are compared with results obtained earlier by other methods. The analysis of 30 mm shaft diameters under the maximum torque of 72.0 Nm shows a factor of safety of 10, while the 20 mm shaft diameter under the same torque gives a factor of safety of 2. This will provide designers guidelines to forecast the design on fatigue strength of a machine shaft.