Research On Nonlinear Dynamics Of Torsional Vibration System Of Rotating Machinery Shafting

In the field of industry and agriculture,the rotating machinery is a very wide range of mechanical equipment.With the continuous progress of modern science and technology,the demand of rotating machinery is increasing day by day.Its safety and stability are the focus of current research.In the course of theoretical analysis of its internal structure,it is found that there are many nonlinear random vibration characteristics of the torsional vibration system of the rotating machine shaft.Therefore,it is important to study the dynamic characteristics of the torsional vibration system of the rotating machine shaft to ensure the smooth and fast operation of the equipment.The model of the torsional vibration system of diesel engine shaft is modeled as two discs and three discs.By using the Lagrange equation in the kinetics of electromechanical analysis,the nonlinear vibration differential equations are established for the two models of the system.The mathematical model of diesel shafting torsional vibration strong nonlinear system of modular two discs system were analyzed.The MLP method is used to solve the primary resonance,the 3 super harmonic resonance and the 1/3 sub harmonic resonance of the system,and the amplitude frequency response equation of the system is obtained by analyzing the system in the case of n=2 and n?2.The parameters of the system are changed one by one,so as to get the effect of the system response characteristics.In the analysis of the main resonance of the system,two kinds of nonlinear analysis methods are applied,namely MLP and modified multiple scale method.Due to the different time scales,the elimination of long term conditions and different solution,resulting in the system of amplitude frequency response equation is slightly different.The response characteristics of the primary resonance and primary parametric resonance of diesel shafting torsional vibration strong nonlinear system under narrow-band excitation is analyzed by using the method of modified multiple scales.The amplitude-frequency response equation of the torsional vibration system of the diesel engine shaft is obtained,and the Ito differential equation is derived,and the approximate expression of the second moment of the system is obtained by using the moment method.The mathematical model of diesel shafting torsional vibration of multiple degree of freedom system model into three discs system were analyzed.By applying the modified multiple scale method,the system's amplitude frequency response equation is obtained by analyzing the two cases of the double resonance of the system without considering the damping term.It is found that the 1:2 internal resonance of the system limits the amplitude infinity when the damping term of the torsional vibration system of the diesel engine shaft is not taken into account.