Study on the Method of Fatigue Test Loading Spectrum of the Connecting Rod in Diesel Engine

摘要

Based on flexible multibody system dynamic theory, founded the rigid-flexible coupling multibody dynamic analysis model of the crank and connecting rod mechanism of diesel engine which included the piston, link, crankshaft and flywheel. The dynamic stress of the connecting rod was calculated and counted by the rain flow method. Counted the stress histories of the connecting rod at all the mission profiles, and then extrapolate and superpose the rain flow matrix, get the stress cumulative frequency distribution of the dangerous node. The load spectrum for the fatigue test of the connecting rod was established, and the mew method can be used for making the specification of the fatigue test of the connecting rod. The load spectrum for connecting rod fatigue test, which can reflect the fatigue life more accurate.