Effect of loading environment on rubber bolster springs used in railway vehicle bogies

The bolster springs investigated have been used in pairs, fitted at an angl e to a bolster beam system for bogies of metro railway vehicles. The produc t has been used for over thirty years, but recently some springs have shown splits and degradations. A finite element analysis was conducted to identi fy the causes. Three normal road cases (tare, mean, and laden load) and thr ee combined load cases were investigated. A stiffness curve from the finite element model was compared with test results, which showed good agreement. Natural frequencies and mode shapes were analysed. Two potential degradati on areas from the combined load cases were located. The critical areas foun d from the stress analysis were the same as those exhibited on the actual s pring components in service. It is shown that the finite element analysis m ethod can pray an important role at the design stage and for failure analys is.