Research On Experiment And Numerical Simulation Of Dynamic Characteristics Of Steel Spring Floating Slab Track

Steel Spring Floating Slab Track(SSFST)has been paid special attention due to its outstanding vibration damping performance.Based on the drop hammer impact method,this thesis takes two sizes of prefabricated SSFST(3.6m and 4.8m)as an example,and the research on dynamic characteristics experiment and numerical simulation are carried out.The specific research contents and main achievements are as follows:(1)The vibration damping performance test of SSFST is carried out,and the dynamic response analysis of the SSFST foundation under different installation conditions and fatigue load times is achieved by using the drop hammer method,and the vibration damping mechanism of the SSFST structural vibration isolator is analyzed.The results show that the vibration damping effect of the vibration isolator is mainly reflected in the middle and low frequency bands around 16～400Hz,and the vibration damping effect can still be maintained above 20 d B after 10 million fatigue loads.(2)Acceleration measuring points are arranged on the rail,track bed and foundation of the SSFST system,and the attenuation and transmission law of vibration waves between the rail,the track bed and the foundation are analyzed.The results show that the vibration wave will gradually attenuate during the transmission of different track components,and the vibration transmission between the rail,the track bed and the foundation has a certain correlation in the frequency domain;After the vibration isolator is installed,the vibration transfer of the rail-track bed increases,while the vibration transfer of the track bed-foundation decreases and there is a transfer peak point at 10 Hz.(3)The finite element model of the SSFST under the action of drop hammer impact is established,and the influence of the failure of the track components on the modal and impact response of SSFST is analyzed.The results show that the failure of the track components will lead to the decrease of the modal frequency of the SSFST and the increase of the shock response,and the failure of the edge isolator is the most unfavorable;The shock response of 3.6m SSFST is slightly larger than that of 4.8m SSFST,shear hinge failure has a greater impact on3.6m SSFST,while 4.8m SSFST is more susceptible to isolator failure.