Fatigue Strength Analysis And Crack Research Of An 8L265 Diesel Engine Crankshaft

Diesel engine crankshaft is a force in one of the most complex parts, which bear the force of gas cylinder, reciprocating piston connecting rod set mass and rotational inertia mass inertia force, but also bear the torsional vibration and bending vibration. Therefore, there are alternating crankshaft bending stress and torsional stress, may cause fatigue failure of the crankshaft and crank down the failure range from suspension, while in machine damage or even personal injury. So, how accurate are the crankshaft internal stress, strain, size and distribution of the crankshaft design, improvement and optimization is of great significance.In this paper, we use the crankshaft of 8L265 diesel engine as the research object. First a 3-D model corresponding to practical conditions was set up by using Pro/E. And then it was imported into ANSYS-Workbench and analyzed. The state of deformation and stress of the whole crankshaft was researched on. The fatigue strength of the crankshaft was checked under alternating loads. At the same time, we use the single turn of the crankshaft as the research object, compared the change of the stress and deformation before simplified and simplified. In addition, the influence of structure parameters on the stress concentration was studied, such as the radius of the journal transition fillet, the shape of the journal transition fillet, the thickness of the crank arm and so on. In order to study the effect of cracks on the crankshaft modal parameters, this paper carry out free modal analysis on the whole model of crankshaft. The results indicate the natural frequency and deformation of the crankshaft. Based on this research, the effects of different depth and location of the crack on the modal parameters of the crankshaft are analyzed. The results show that the natural frequencies of the crankshaft reduce with the deepening of the crack depth, but the reduction in the magnitude is different. Through the above analysis and calculation, some valuable conclusions can be made and can provide reference and theoretical basis for the realization of the crankshaft dynamic crack detection and diagnosis.