Transition curve effect on lateral vibration of superconducting experimental maglev bogie: A nonlinear dynamic approach

This paper presents a nonlinear dynamic analysis approach; its aim is to study the effect of the transition curve on the dynamic behavior of the superconducting magnetic levitation UAQ4 experimental bogie. The levitation working principle is based on the magnetic interaction between bulk high-temperature superconductors set on the vehicle and permanent magnets distributed along the track. Numerical simulations of a suspended bogie were conducted by using a three degrees-of-freedom model supported by experiments. First of all, two different mixed rectilinear/curvilinear magnetic track path types, one with transition curves between straight lines and a circular curve and the other without any transition curves between straight lines and a circular curve, were considered and analyzed. Then, a series of parametric dynamic analyses were performed in order to calculate the bogie lateral dynamic response by varying the radius of the circular curve, the length of the transition curves, and the running speed. The results prove that the addition of a right transition curve between straight lines and the circular curve reduces the amplitude of the lateral vibrations of the bogie by several factors, and it consequently allows the bogie's critical running speed to increase over the path. Finally, the results were synthesized in an abacus in order to evaluate the design value of the transition curve length according to the system input parameters.