Material and Stress Analysis of Railroad Vehicle Suspension: A Failure Investigation

Suspensions are the important machine element of rail road vehicle which absorb the shocks and vibration during tracking, curving and also protect the axle movement. The helical compression type of spring is used to allow axial deformation and also provide some lateral deformation at curvature. A freight rail vehicle has the frequent failure of primary suspension with major emphasis on the failure of composite spring of central axle of both frames. The failure investigation starts with the material analysis by experimentation for chemical composition for different failed specimen of springs using spectrometer. It is continued to the stress analysis with respect to the mechanical properties of material by analytical and finite element analysis at various loading conditions. The material and stress analysis revealed that the failure occurs due to design incompetency by increase of stresses at curvature and at maximum tractive efforts at various speed.