Failure Analysis of an Automobile Coil Spring in High-Stress State
- 175 Downloads
The present work details a study for the determination of causes of a prematurely failed automobile spring. Several tools consisting of visual observation, optical microscope, scanning electron microscope (SEM), energy-dispersive spectrometer (EDS) analysis, etc., were used on the failed product to investigate the underlying causes. Photographs of the failed spring showed large wear marks and machinery indentations on the surface. These wear marks indicated an improper installation which could cause additional stresses under service loads. SEM images of one of the indentations showed radiating ridges emanating from the indentation tip which indicated that it served as the fatigue initiation. EDS results showed foreign elements in the fatigue origin implying the existence of microcracks. Under the effect of service and additional load, a stress concentration point was formed and fatigue crack originated from the indentation tip resulting in the final rupture.
KeywordsAutomobile spring Crack initiation High-level stress Fatigue striations Fatigue failure
This work was supported by the National Natural Science Foundation of China (Grant Nos. 51601156 and U1537201) and Fundamental Research Funds for the Central Universities of China (Grant No. 2682016CX067).
- 12.C.S. Hattori, A.A. Couto, J. Vatavuk, N.B. Lima, D.A.P. Reis, Evaluation of Fatigue Behavior of SAE 9254 Steel Suspension Springs Manufactured by Two Different Processes: Hot and Cold Winding, Experimental and Numerical Investigation of Advanced Materials And Structures (Springer, Berlin, 2013), pp. 91–105Google Scholar