Study On Coupled Vibrations Between Carbody And Undeframe Suspended Equipment Of High Speed Trains Based On Power Flow Method

Vibration control is an important sub-discipline in the field of mechanical engineering,and it is also a key step in the actual use of engineering.Classical mechanics theory is the most widely used method in the field of vibration.The use of energy transfer methods has become a hot topic in recent years.Starting with the energy generated by vibration and the transfer relationship of energy,combined with the traditional vibration theory and the basic principles of dynamic theory,the vibration of vehicle suspension equipment are studied.Based on the power flow method,the optimized analysis for studying vibration isolation effects of complex systems has been one of the best methods for studying vibration isolation since the last century.The combination of admittance matrix and power flow analysis method is an effective method to analyze the vibration energy of complex mechanical structures,and it is also a relatively simple way to analyze the vibration damping effect of equipment.The power flow analysis method uses the force and speed of a certain order system.which can be measured in practice,and the energy is a scalar in vibration transmission.Compared with the traditional vibration analysis methods,this method is more convenient and effective.For a complete mechanical system,the energy calculated by the power flow method can also clearly indicate the energy flow direction.Through calculation,energy size of every part can be observed,so that,the researchers can purposeful carry out vibration control and parameters control.In this paper,firstly,through theoretical analysis,the basic equations of the power flow analysis method are listed,the mathematical model of the vehicle system is established,and the resonance frequencies of the single or multiple suspensiond devices for both the rigid body system or rigid-flexible coupling system are calculated,and the force and energy are analyzed in the system.In the transfer relations,the vehicle dynamics equation is deduced and calculated.The admittance and impedance matrices of each subsystem are obtained by the four-terminal parameter method,and substitutting into the power flow equation.Using the calculation simulation software,the vibration isolation device is calculated for each stage.Then the power flow frequency and response curve of the car body is obtained,and the influence of certain parameters on the damping effect of suspension equipment is systematically studied.After analysing the changes in the damping,stiffness,and mass of the under-frame suspension equipment and the car body itself,the input energy change trend to car body is analyzed,and the vibration damping effect of a certain parameter on the underframe suspension equipment to the vehicle body is verified.The power flow curves of the rigid and rigid-flexible coupling systems of the vehicle system are calculated and the theoretical research is combined with the actual conditions to obtain the power flow curves of the two different systems.The reasons for the different shapes of resonance peaks are analyzed.Through theoretical analysis and actual engineering comparison,key factors that have a great impact on the vibration isolation system are proposed.