Improvement of curving performance of railway vehicle by axle box suspension with variable longitudinal stiffness

In order to improve the running performance of a railway vehicle, the authors developed the axle box suspension with the magnetic elastomer. The magnetic elastomer is composed of magnetic particles and the elastomer such as synthetic rubber. This material is characterized by its hardness variation depending on the magnetic field. In this paper, the authors synthesized the bimodal magnetic elastomer containing nonmagnetic particles. In a characteristic test, the authors confirmed that Young's modulus of the magnetic elastomer changed in the range of about 2.2 times depending on the magnetic field. Moreover, the authors carried out a running test on a test line of the MIHARA Test Center. The authors confirmed that the axle box suspension with the magnetic elastomer were able to secure the running stability at 70 km/h without causing an unstable state. In addition, the authors carried out a running test on a test line of the Railway Technical Research Institute. The authors confirmed that the axle box suspension with the magnetic elastomer were able to reduce the outer lateral force of a leading wheelset.