The three-layered conic rubber spring (CRS) is a unique and very important part of the axle-box supporting system used for commuter trains. We investigated the deterioration of the dynamic properties of CRS such as a dynamic spring constant (DSC) and its influence on the stability of vehicle motion. The results of acceptance sampling and accelerated deterioration tests show that accumulated load and temperature are estimated to be a factor of CRS deterioration. The DSC of a CRS used for 12 years increased to 2.5 times the initial static value. Numerical analyses of a one-body model indicate that increases in DSC can decrease the critical speed of hunching.

Copyright (c) 2004 Railway Technical Research Institute