Finite element analysis on bolster springs for metro railway vehicles

The bolster springs investigated here were used in pairs, fitted at an angle to a bolster beam system for metro railway vehicles. The product has been used for over thirty years but recently some springs have shown splits and degradations. A finite element analysis is conducted to identify the causes. Three normal load cases (tare, mean and laden load) and three combined load cases were investigated. A stiffness curve from the FE model was compared with test results, which has shown good agreement. Natural frequencies and mode shapes were analysed. Two potential degradation areas from the combined load cases were located. The critical areas found from the stress analysis were the same as those exhibited on the actual spring components in service. It is shown that FEA method can play an important role at design stage and for failure analysis.