Failure Analysis of a Medium Duty Vehicle Leaf Spring
Authors: Gül Çevik
This paper summarizes the work conducted to assess the root cause of the failure of a medium commercial vehicle leaf spring failed in service. Macro- and micro-fractographic analyses by scanning electron microscope as well as material verification tests were conducted in order to understand the failure mechanisms and root cause of the failure. Findings from the fractographic analyses indicated that failure mechanism is fatigue. Crack initiation was identified to have occurred from a point on the top surface near to the front face and to the left side. Two other crack initiation points were also observed, however, these cracks did not propagate. The propagation mode of the fatigue crack revealed that the cyclic loads resulting in crack initiation and propagation were unidirectional bending. Fractographic analyses have also showed that the root cause of the fatigue crack initiation and propagation was loading the part above design stress. Material properties of the part were also verified by chemical composition analysis, microstructural analysis by optical microscopy and hardness tests.
Digital Object Identifier (DOI): doi.org/10.5281/zenodo.3566363Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 618
 S. Kalpakjian and S.R. Schmid, Manufacturing Engineering and Technology, Dorling Kindersley Pvt Ltd, 2011, pp. 340-341.
 G.F. Vander Voort, Advanced Materials and Processes, ASM International, 2015, 127(2), pp.22-25.
 A. Bramley and K.F. Allen, Engineering (London), Vol 133, p 92-94, 123-126, 229-231, and 305-306, 1932.
 J.K. Stanley, Iron Age, Vol 151, p 31-39 and 49-55, 1943.
 G.A., Hamkin and M.H. Becker, Journal of Iron and Steel Institute, 125, 1931, p387.
 A.S. Kenneford and G.C. Ellis, Journal of Iron and Steel Institute, 164, 1950, p265.
 R.L. Mattson and J.G. Roberts, SAE Transactions 68, 1980, pp. 130-136.
 W. Koenecke, N.K. Burrell, and C. Mehelich, Metal Improvement company, Paramus NJ ,Subsidiary of Curtiss-Wright Cooperation, October 1982, Spring, Technical Article #1982016.
 N. Chakraborti, B. Siva Kumar, V. Satish Babu, S. Moitra, and Mukhopadhyay, Proceedings, 14th International Workshop on Computational Mechanics of Materials, 2006.
 N. Jin and S. Y. Zhou, Transactions of the North American Manufacturing Research Institute of SME 32, 2004.
 S. K. Biswas, S. J. Chen and A. Satyanarayana, Journal of Dynamical and Control Systems, vol. 7, 1997, pp. 327-340.
 J. Xu, D. Zhang and B. Shen, International Conference on Shot Peening-I, 1981, Paris. 1981074, pp.367-374.
 B. Sustarsic, P. Borkovic, W. Echlseder, G. Gerstmayr, A. Javidi and B. Sencic, Journal of Structural Integrity and Life V.11.1, 2011, pp.27-34.
 C.K. Clarke and G.E. Borowski, Journal of Failure Analysis and Prevention, V5(6), December 2005, pp54-63.
 ASTM E112-13, Standard Test Methods for Determining Average Grain Size, ASTM International, West Conshohocken, PA, 2013, www.astm.org.