Borg Ballastless Slab Track Vertical Dynamic Analysis

With the rapid development of passenger dedicated lines and citymass transit in China, ballastless track which character is higherstability, less maintenance and mature technique was developed rapidly, itis necessary to analyze the dynamic properties of ballastless railways.This paper focuses on the the B(?)gl slab track, and the B(?)gl slab trackand track are viewed as a whole system,then a B(?)gl slab track andvehicle vertical coupling dynamic modle is established.In this paper, B(?)gl slab track is sepatated as 22-degree-of-freedomfinite element. The track between every adjacency two fastener is treatedas an element,in which the rail is simulated as continuity-point-suportingEuler beam, the cushion of the rail is simulated as line spring anddampers, the track slab is simulated as elastic plates, the mortar issimulated as line-distributed-diaphragm-flexure and dampers. The vehicleis simulated as 6-freedom multi-body model. The equations describingthe movement of the train-track vertical vibration system are formulatedon the basis of minimum potential theory and "sit in the right seat"principle,and simulating program is constructed accordingly.On the basis of the track vertical free vibration model,the freevibration of the BOgl slab track is analyzed in this paper by means ofsubspace iteration method. The vertical free vibration frequency andvibration mode between first five steps are put forward.and thecalculating results are proved to be correct and reliable. The free vibrationanalysis can check the correctness of the track vibration model.With the vertical irregularity as vertical vibrating resource, the train-B(?)gl slab track vertical vibratory responses are analyzed, and sometime-history dynamic response curves of the system are put forwardwhich manifest B(?)gl slab track structure dynamic characteristic.On the basis of the train-track model,a study of parameter work isprocessed,which is mainly about the effects of the spring stiffness of railsupport,vertical damping between rail and slab, the thickness of the slaband the elastic modulus of the slab on the vertical vibration displacementand acceleration of the rail,slab,train barycenter, former bogie and thewheel/rail force.the appropriate value of some rail parameters are obtained.By comprehensively considering, the reasonable spring stiffnessof rail support is 4×10~7～6×10~7N/m; the reasonable vertical damping ofthe cushion under the rail is 1×10~5～3×10~5 N.s/m;the reasonablethickness of the track slab is 0.2m;the reasonable spring between the carbody and the bogie is 2.5e6N/m; the reasonable spring between the bogieand the wheel is 1.52e6N/m. The concludes is be propitious to B(?)gl slabtrack structures designing.