Vibration Isolation Analysis And Suspension Parameter Optimization Of Railway Passenger Vehicle Systems

Because of the advantageous of fast speed, comfortable ride, high efficiency, safety and reliable, the high speed train are widely developed in the world and great achievements are made. The high speed train is also carefully studied in our country. But with the development of high speed train, it brings out a lot of new dynamic problems. In this thesis, vibration isolation and suspension parameters optimization problems for high speed passenger car are studied, which is meaningful both in theory and engineering application.In traditional vehicle model, spring and damper are usually parallelly arranged. In fact, there are rubber nodes on both sides of damper in the passenger car system. So the exact model should be that the damper connected with two springs on both sides in series, then parallel with the main spring, which we called extended Ruzicka model. In the past, normally single parameter optimization under single aim is considered for suspension parameter optimization. And the parameter optimization of interconnection suspenstion between cars is rarely studied. Actually the cars are coupled together especially for the high speed train set, the interconnection suspenstion parameters should be investigated. The suspension parameters are coupled with each other and they work together on cars. Maybe there is an optimized value or zone for suspension parameter. Thus, it is necessary to study this kind of problems in detail.In this thesis, an extended Ruzicka isolation model for railway passenger car is set up, which is more accurate compared with the traditional passenger car model. Vibration reduction and isolation theory is used to study the difference between the two models. The necessity of using this accurate model is described. The optimization problems with multiple aims and multiple parameters for vehicle vertical model, vertical and lateral coupled model and train model are studied by using the evaluation function method in order that the minimum displacement and acceleration of car-body can be obtained. Punish function is used to constrain the value of suspension parameters not exceeding the select range.Harmonic and randomvibration isolation theory is used to study the vibration features of railway passenger car system.Through numerical computations, it is known that harmonic vibration isolation is different from random vibration isolation. Speed, PSD and power factor have different effect on the selection of suspension parameters.At the end of this thesis, the conclusion can be drawn that the suspension parameters have great effect on passenger car dynamic behaviour. The primary and secondary suspension parameters contribute much on system dynamic behavior compared with the car-body end suspension parameters, and secondary suspension parameters are more important than primary suspension parameters. There are optimum solutions for suspension parameters.The work of this thesis provides a new and efficient method for the selection of suspension parameters of railway passenger cars.