| Rail transit vehicles are composed of carbody,bogie and so on.The bogie contacts the rail through the wheelset and bears various loads.The track irregularity will cause the vibration of wheel-rail interface,and the elastic vibration of the bogie and other load-bearing components will inevitably occur under the external excitation,which will aggravate the force between the components and cause the wear and damage of the components;moreover,these vibration will be transmitted to the carbody,affecting the comfort of the vehicle.Therefore,it is necessary to study vehicle dynamics considering structural elasticity.In this paper,SIMPACK software is used to establish a multi-rigid-body dynamic model of a certain type of vehicle,and then ANSYS software is used to carry out modal analysis of the flexible body,establish the flexible body model,and carry out eigenvalue analysis.The difference of wheel-rail contact characteristics between rigid and flexible body models is compared.The vibration acceleration and frequency distribution characteristics of axlebox,frame and carbody on straight line and curve,as well as the transmission process of vibration and force are analyzed.Finally,the joint simulation results of MATLAB/Simulink and SIMPACK are compared with the above results.The following results and conclusions are obtained.In the aspect of wheel-rail contact,compared with rigid body model,the range of change of wheel-rail contact point of flexible body model is smaller and the range of change of wheel-rail contact force is larger,and the lateral force of wheel-rail is about 35%larger than that of rigid body model.The vertical force of the flexible body model wheel-rail has a peak value of 28.83 Hz caused by the wheel rotation frequency.The vibration frequencies of axlebox,frame and carbody of flexible body model all appear,and most of them are dominant frequencies.In addition,besides the vibration caused by wheelset rotation and track plate,there are also obvious vibration caused mainly by the structural modal of the flexible frame.Except for the 28.83 Hz vibration of the flexible body model,there is no obvious difference.The wheel-rail force characteristics of the two models on the curve are slightly different from those on the straight line.In addition,the vibration acceleration of the axlebox,frame and body of the two models decreases by an order of magnitude from bottom to top.The power spectral density decreases by an order of magnitude from the axlebox to the frame,and by two orders of magnitude from the frame to the carbody.The lateral and vertical vibration accelerations of the axlebox of the flexible body model are 13.7 times and 2.7 times of those of the rigid body model,and the lateral and vertical vibration accelerations of the frame are 3.8 times and 1.5 times of those of the rigid body model,but there is little difference between the two models.The frequency distribution and transfer law of acceleration on the curve are consistent with those on the straight line.The vibration of axlebox and frame of the two models can stabilize the vehicle system through the attenuation of primary and secondary suspensions.It can be seen that the bogie flexibility has a great influence on the dynamic contact characteristics of wheel-rail and the vibration of vehicle system. |
PDF Full Text Request