The Torsional Vibration And Fatigue Analysis Of The Engine Crankshaft System

As one of the important parts of engine crankshaft, the vibration problem has been people research hot spot and the difficulty.At the same time, the torsional vibration of internal combustion engine crankshaft system is a branch of mechanical vibration discipline.With the development of the engine technology and higher comprehensive performance requirements, the engine to improve the performance of harshness(NVH) is particularly prominent.This paper,based on this research background,takes the in-depth research on the crankshaft torsional vibration and fatigue life.This topic main works are as follows:(1)Using UG software to build 12v150 three-dimensional entity model of the crankshaft and Using the software function model analysis to determine the parameters of material characteristics and quality characteristics.On this basis,In combination with crankshaft torsional vibration model simplification principles and methods,crankshaft torsional vibration multidimensional lumped parameter model is established.(2)Crankshaft torsional vibration analysis and study of free vibration.According to d’alembert’s principle of establishing the differential equation of free vibration of the crankshaft and Using MATLAB software to solve differential equations,get free vibration under each order natural frequency and the quality of the relative amplitude and its main modes diagram for the back of the crankshaft forced vibration analysis to do data base.(3)Vibration source of harmonic analysis.Using the method of Fourier transform takes harmonic analysis on the main cause of crankshaft torsional vibration gas explosion pressure.Get the torsional vibration caused by the harmonic disturbance torque,as well as the critical speed and the harmonic frequency range taken into account.(4)Crankshaft torsional vibration forced vibration response analysis.According to the principle of d ’alembert,establish crankshaft forced vibration differential equation and use numerical calculation method of transfer matrix to solve differential equations to get the quality of the relative amplitude and its main modes diagram.Under interference torque of forced vibration of crankshaft is analyzed(5)The torsional vibration of crankshaft system control.Design silicone oil reverse shock absorber.Through the calculation of the shock absorber performance analysis,the crankshaft vibration response results are obtained.By comparing the crankshaft torsional vibration damper forced vibration response,the effect of crankshaft torsional vibration damper damping is analyzed.(6)The analysis of crankshaft fatigue strength.The static strength of the crankshaft is analyzed by the ANSYS software to get the stress and strain of the crankshaft under maximum force results.It is concluded that the crankshaft design satisfies the requirement of strength.The stress results by the ANSYS software to analysis are imported into the Fe-safe software for calculation and analysis of crankshaft torsional fatigue to get the crankshaft fatigue in the standard condition.Also a method of simulation research is provided for crankshaft torsional vibration fatigue analysis.