| Due to the characteristics of large volume,effective reduction of transportation cost and high transportation potential,heavy haul railway has gradually replaced passenger-freight mixed transportation railway and become the mainstream of transportation industry development in major railway countries around the world.At the same time,curvilinear bridge is more and more widely used in railway,and the vehicle-bridge coupling problem caused by train running on curvilinear track has become a hot research topic in railway bridge field.Considering that the vehicle-bridge coupling vibration analysis of heavy-haul railway combined with small radius curved beam bridge is not thorough enough,the dynamic response of trains passing through curved bridge under different small radius track(radius less than 1000m)is lack of detailed analysis.Therefore,in this paper,with a variety of small radius curve track(300m,600m,900m)as the background,further research on the vehicle-bridge dynamic coupling vibration of heavy train passing through the curve beam bridge.The multi-body dynamics simulation analysis software SIMPACK was used to establish the heavy-haul train model,and the finite element software ANSYS was used to establish the rigid curved continuous girder bridge model and the curved rail three-dimensional space model.The rigid curved continuous girder bridge model and the threedimensional rigid rail model were imported into SIMPACK software through data conversion to generate the flexible body.The dynamic analysis model of curvilinear beam bridge-railway-train coupling system is established.Based on this model,vehiclebridge coupling vibration analysis of curvilinear girder bridges of heavy-haul railways under different small radii is carried out.The main research work and conclusions are as follows:(1)SIMPACK software is used to establish the dynamics model of two-system suspension four-axle heavy load train.The curve track rigidity model is established by ANSYS software,and its substructure is analyzed to generate(*.fbi)file,and then combined with flexible track specific(*.ftr)configuration file call(*.fbi)file,the curve track rigidity model is generated in SIMPACK flexible curve track body;the fifth order spectrum is used to generate orbit irregularity as external excitation.The orbit of circular curve segment is connected with the orbit of straight line segment by using cubic parabolic easing curve,and the ultra high value and ultra high type at the junction of easing curve and circular curve segment are defined.The coupling between train and flexible track is realized by the wheel-rail contact relation.(2)Using ANSYS software for continuous girder bridge model rigidity,small radius curve generated through substructure analysis of flexible body input file,with the aid of data transformation,the curve bridge rigidity model into the SIMPACK software generated in the flexible bridge,with trains and the flexible curve orbit model,establishing curve girder bridge-track-train coupling vibration dynamics analysis model.ANSYS and SIMPACK software are used to analyze the natural vibration characteristics of the bridge.The results show that the natural vibration frequencies calculated by ANSYS and SIMPACK are basically consistent.(3)Based on the above dynamic analysis model of curvilinear bridge-railway-train coupling vibration,the vehicle-bridge coupling vibration analysis of small radius curvilinear bridge of heavy-haul railway is carried out in SIMPACK software,and the influence of curvilinear bridge position on circular curvilinear track and the influence of curvilinear bridge radius on vehicle-bridge coupling dynamic response is studied.The results show that:1)When the bridge overlaps with the starting point of the circular curve track,the peak value of vertical displacement in the middle of the bridge girder span is the smallest.With the increase of the distance between the bridge and the starting point of the circular curve track,the peak value of vertical displacement increases gradually.On the contrary,the peak vibration acceleration of the main beam decreases in horizontal and vertical direction.2)The peak values of vehicle safety performance index and vibration performance index decrease with the increase of the distance between the bridge and the starting point of circular curve track.3)When the distance between bridge starting point and circular curve track starting point exceeds 110m,the peak values of vehicle safety performance index and vibration performance index tend to be stable.4)Compared with the curve radius of 600m and 900m,when the radius is 300m,the vibration response peak value of the vehicle is larger,but the peak value of the vibration acceleration of the bridge in the vertical and horizontal direction is smaller.5)With the increase of radius,the increase of peak values of various indexes of the bridge slows down,and the peak values of various dynamic response indexes of the vehicle show a decreasing trend. |
