Citation

Kumbhalkar MA, Bhope DV, Vanalkar AV, Chaoji PP. J. Fail. Anal. Prev. 2018; 18(6): 1447-1460.

Copyright

(Copyright © 2018, ASM International, Publisher Holtzbrinck Springer Nature Publishing Group)

DOI

10.1007/s11668-018-0542-1

PMID

unavailable

Abstract

WAG-9-type electric rail vehicle, of Indian Railways' fleet used for goods train hauling and maintained at Ajani, Nagpur Electric Loco Shed of central railway, has a history of frequent failure of middle axle primary inner suspension spring. The study of failures revealed that this specific component fails at a very high rate. The failure investigation starts the experimental spectroscopy analysis to find chemical composition for different failed specimens of springs, and it is observed that all parameters are within the recommended range. Also the stiffness of primary middle axle and end axle suspension springs has been checked on spring testing machine to measure deflection of spring, and it is as per recommended values. Further static stress analysis is carried out using analytical and finite element analysis for various phases of operation of rail vehicle like straight track, curved track and also for tractive effort. The static stress analysis has not revealed the cause of failure, and hence the dynamic analysis is performed. For dynamic analysis, dynamic model of suspension system is considered and analyzed using analytical method, finite element method and using MATLAB Simulink model. The vibration response of actual suspension system is also measured using FFT analyzer. It has been seen that the frequency of excitation and the natural frequency of the system are very close to each other which has resulted into suspension vibration amplitude of 6-8 mm. Fatigue analysis is carried out using finite element method to investigate the effect of dynamic loading on the failures of suspension spring. This analysis revealed that the middle axle inner suspension spring has finite life and due to which spring failure occurs earlier.

Language: en

Keywords

Fatigue analysis; Indian Railway; Primary suspension spring; Spectroscopy analysis; Vibration