FEM Analysis Of Static Strength For A Crankshaft Of A High Power Diesel Engine

Crankshaft is a critical component in the high power diesel engines. Its technical characteristics determine the performance and service life of diesel engines to a large extent. During the operation, the failure of crankshaft always represents as the plastic deformation or fatigue fracture at a specific position on the crankshaft. Thus, the strength analysis of crankshaft is especially important.With the development and application of computer science, especially the computation mechanics, the finite element method is preferred to be used widely in the strength analysis and optimization for the complicated mechanic structures due to its short period, low cost, and reliable analysis results. The finite element analysis software named ANSYS is applied to perform the strength analysis for the crankshaft of a high power diesel engine in this thesis, in which, sub-model technique is used to improve the calculation precision and analysis effectiveness, and 3-dimensional finite element contact analysis is adopted to simulate the boundary cutting condition between the master model and sub-models for making the structure simulation more integrated and exact.Thesis content includes: building up the finite element analysis model, conducting the movement characteristic analysis, determining the boundary conditions of displacement and load, ensuring the dangerous working condition, performing the finite element analysis of strength, checking the safety factors of static strength, and using the self-compiled program to check the safety factors of fatigue strength under two load-combined working conditions.Analysis results of this thesis comply with the practical operation of crankshaft of the high power diesel engine, which proves that analysis results are reliable and analysis methods are available. Furthermore, it is innovative of using sub-model technique and 3-dimensional contact technique to perform the strength analysis of crankshaft. It is also very innovative of using the self-compiled program to check the safety factors of fatigue strength under two load-combined working conditions. Analysis data in this thesis provide the available information for the design and optimization of structure parameters and the performance improvement for crankshafts. Besides, they establish the base for improving the performances of the locomotive diesel engines in our country and provide an available analysis method for the strength analysis of complicated mechanic structures.