Vibration Analysis Of Diesel Engine Based On Multi-Body Dynamics And Fatigue Life Prediction Of Crankshaft

Diesel engine is the basic power device of car, locomotive, construction machinery, ships, etc. Since1950s, the number of diesel engine is increasing every day and people have more and more demandings on the improving of diesel engine. With the continuous improving of the strength norm, working conditions of the working parts become more complex, people pay more and more attention on the problem of vibration and noise generated by diesel engine. For reducing the vibration and noise of diesel engine, traditionally, people pay much attention on the precision of model and simulate force, so as to improving the precision of all parts dynamic response, but people pay less attention on the machine modle analysis and dynamic response analysis. Therefore, the detailed analysis is conducted with a machine model based on multi-body dynamics and fatigue resistance is conducted with the crankshaft. This paper is to explore a more precise way to evaluate the dynamic properties of the crankshaft.This paper select a6-cylinder diesel engine as research object and builds a rigid-flexible coupling multi-body dynamic model using software ADAMS and ANSYS in which crankshaft and block are flexible bodies, cylinder head and connecting rod are rigid bodies. The machine model dynamic analysis is compared with the model analysis of crankshaft and block in ADAMS, and analyze the main reasons that result in virbration of disel engine. Based on statics analysis of crankshaft, the fatigue resistance of crankshaft with different working conditions is checked with FE-SAFE. The conclusion is that the machine model analysis is more accurately reflect the working conditions. This paper also indicates that the dynamic properties of the diesel engine and fatigue resistence of the crankshaft meet the design requirements.Through the work mentioned, it can be seen that multi-body dynamic theory can more accurately reflect the real working conditions and evaluate the dynamic properties of the diesel engine. It can further improve efficiency, save development costs and enhance product properties during the diesel engine designing.