The Fatigue Strength Analysis Of Crankshaft For Diesel Engine

As the most important motional element of a diesel engine, the durability and efficiency of a diesel engine is relied on the crankshaft to a large extent. For the crankshaft worked under the condition of multiple-spindle pulsating stresses, and the orientation of the main stress changed as the cyclic loading variation. According to 16PA6STC diesel engine crankshaft, the article analyzes the fatigue strength under the rated operating condition, base on the dynamic simulation and finite element method. The main contents of this thesis are given as follows:First, the Pro/E software is applied to set up 3D model of the crank-rod mechanism, and assemble the gear by the interface of Pro/E software. The model can be imported into ADAMS. Virtual Prototype of 16PA6STC diesel engine motivation mechanism established.Second, the crankshaft finite element model is built by utilizing the Hypermesh software, analyzing the vibration mode characteristic data and the static strength of the crankshaft by using Patran/nastran FEA software. Meanwhile, the crankshaft is changed from rigid body into flexible body at the FEA process. The multi-body dynamics model that combining rigid to flexible bodies was established utilized ADAMS software. Simulations were done on the dynamics, kinematics of the crank-rod mechanism of a marine diesel under the rate condition, and the dynamic characteristic data of the crank-rod mechanism are derived.Then, the fatigue life of the crank shaft is calculated using of load spectrums from previous step. Result show that the minimum fatigue life and the minimum safety factor on the key section of the crankshaft.Finally, a concrete model of the law of cumulative damage got that description of the diesel engine crankshaft, and identified the calculated fatigue life result through experiments data in the references.It provides the valuable reference result of improving reliability for diesel engine, and optimizing the structure of the crankshaft by adopting of Computer Aided Engineering (CAE) technology.