Research On The Dynamic Effect Of New Type Medium-low Speed Maglev Train-transport Rail-beam

In this thesis,the new type medium-low speed maglev train-transport rail-beam is taken as the research object.The theoretical and finite element calculation results of the electromagnet levitation force are analyzed.The modeling method of the levitation foce is analysed.The levitation force of the levitation force element is still based on electromagnetic computing,but the distributed levitation force can be reduced to a different number of concentrated forces,which is different from the conventional simplification of the levitation force as spring damping force element.The new type levitation bogie is introduced.Based on the new type medium-low speed maglev train and a medium-low speed maglev tourism line,the line is further refined into transport rail and beam in the train-line coupled vibration system.Based on the finite element method and the multi-body dynamics method,the new tpye medium-low speed maglev traintransport rail-beam coupling dynamics model is established.The dynamics calculation results of maglev train with different numbers of maglev force elements are compared.The influences of the longitudinal level of transport rail(10 m chord vector height),the allowable deviation of the transport rail joints(vertical),and the vertical stiffness of the transport rail fasteners on the dynamic effects of the system are studied.The following conclusions are reached:The electromagnetic levitation force is proportional to the square of the gap magnetic flux density .The gap magnetic flux density is evenly distributed over the length of the levitation electromagnet,and the levitation force distribution law is obtained.It is proved that levetation force simulation with n simplification force elements is feasible in engineering practice.The force of the levitation module with the n levitation force elements under track irregularities excitation at different wavelengths is studied.The results show that the three force elements model can better simulate the force of the levitation module.The new type medium-low speed maglev train adopts air springs centered structure,which effectively reduces the dynamic effect between the car body and the levitation bogies.The new type levitation bogie structure adapts to the extended linear motor and reduces distance between the adjacent linear motor.So,it can meet the running speed of 160 km/h.A single set of antirolling beams and two levitation modules form an "H" structure,which realizes more sufficient decoupling of the left and right levitation modules.The new type medium-low speed maglev train can achieve faster speed and lower dynamic effect.Simulation calculations are performed on the dynamics model of the new type medium-low speed maglev train with different numbers of levitation force elements,and the key dynamics indicators such as the levitation gap and vertical acceleration of the levitation bogies are compared.It is found that the calculation of the three force elements model is more accurate and the calculation speed is faster.The rationality of the three force elements dynamics model is verified,and this conclusion is applicable to the EMS train.The accuracy of the new type medium-low speed maglev train-transport rail-beam coupling dynamics model established in this thesis is verified by experimental measured data.The longitudinal level of transport rail(10m chord vector height)has a greater impact on the ride index of the train.And the negative deviation has a greater impact than the positive deviation.The allowable deviation of the transport rail joints(vertical)has a greater impact on the levitation gap and the maximum vertical acceleration of the levitation bogies.The allowable deviation of transport rail joints(vertical)should be controlled within ± 2 mm.The vertical stiffness of the transport rail fasteners has a greater impact on the maximum vertical acceleration of the F rail at the joint and the dynamic coefficient of the middle of beam span.