Study On Periodicity Of The Vibration Of The Track Structure

People put forward higher requirements for comfort and safety of the railway traffic,which forces us to spend more efforts on the study of vibration of the railway.The most basic vibration of the track structure is caused by the periodicity of the track structure itself and the periodicity of the loads.People may ignore these vibration,while pay more attention on the vibration caused by irregularity of the track structure.The paper analyzes the vibrations of the track structure without irregularity,and the main research contents and achievements are as follows:1 ? According to comparison of calculation methods of vibration,we know the mechanism of the vibration of the track structure.Finally,the finite element models for the coupled vertical vibration of the four systems of vehicle-ballasted track,vehicle-CRTSI slab ballastless track,vehicle-double block ballastless track,and vehicle-CRTSIII slab ballastless track were established with the help of dynamic simulation software.The paper analyzed the vibration of the track structure without irregularity under four different working conditions.2?The strength of vibration of the four different track structure without irregularity were investigated.It was found that even if there is no track irregularity,there is still a certain amount of vibration in each part of the track structure.The result lays the foundation for everyone to better understand the vibration of the track structure in the future.3?The vertical vibration laws of the track structure type is studied in the frequency domain.The paper studies the factors which affect the vibration intensity of the track structure according to the correspondence between wavelength of the vibration wave and the size of the train,or the size of the track structure.The research shows: The vertical acceleration of the rail is mainly affected by the fixed wheelbase of the train,while the vertical acceleration of the structure under the rail is mainly affected by the spacing of the fastener.The most important factor affecting the wheel-rail interaction force is the fastener spacing of the track structure.And the most important factor affecting the dynamics of fasteners is the center distance of the bogies of the train.4?To investigate the relationship between the vibration intensity of each part of the track structure and the running speed of the train,the paper analyze the vibration of the track structure when the train running speed is 160km/h,200km/h,250km/h,300km/h,350km/h without track irregularity.The research shows: As the train speed increases,the vertical acceleration of the rail increases.The increase of driving speed will aggravate the interaction between wheels and rails,and accelerate the damage to the track structure.With the increase of train running speed,the strength of the dynamic reaction of the fasteners in the time domain is not much different.However,in the frequency domain,the spectrum value of the dynamic response of fasteners increases first and then decreases with the increase of the speed.