Development of a smart rubber joint for train using shear thickening fluids

Developing a train bogie to achieve high speed stability as well as good curve passing performance has always been a challenge. This is because of the conflicting stiffness requirements: Stability at high speed calls for a high primary longitudinal stiffness in bogie design, whereas for better performance through curves, a relatively soft primary longitudinal stiffness is required. To solve this parameter incompatibility, this paper proposes a new design which uses the shear thickening fluid (STF) structure as the stiffness changing component. This new joint was developed and then tested using MTS machine to characterize its frequency-dependent characteristics. MTS testing under varying displacement amplitude at fixed frequency was also performed to investigate the influence of the varying amplitude on the effective stiffness. At last, the performance of the proposed STF joint in terms of improving the train stability and the curving performance is numerically evaluated. The numerical evaluation results demonstrate that the adaptive STF rubber joint outperforms the conventional rubber joints in that it can satisfy the conflicting stiffness requirements to simultaneously achieve high speed stability and curve trafficability.