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Fatigue Life of a Rocker Arm Using Calibrated Accelerated Life Test Approach
Technical Paper
2021-26-0453
ISSN: 0148-7191, e-ISSN: 2688-3627
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English
Abstract
Fatigue life estimation of mechanical components with a complex geometry is generally carried out using statistical methods. The commonly used approach in the industry is the staircase method using ISO12107. As per this standard, staircase approach requires fifteen samples for exploratory testing to build the S-N Curve, eight of these being used to estimate the S-N curve in the finite fatigue life range (inclined line) and seven for the fatigue strength at the infinite life regime (horizontal line). In this paper, staircase approach is compared with calibrated accelerated life test (CALT) to predict the fatigue life of an engine valve train ‘rocker arm’ is discussed, which is very effective in predicting fatigue life, and reduce the test time significantly and quantifying reliability. The CALT test is performed with multiple samples at each of the multiple stress levels till failure, and the expected lifetime at the normal stress is estimated based on all the test results. The fatigue life prediction of rocker arm is compared with the conventional staircase approach. The comparison of the test results of both approaches shows that the CALT method shows similar results for fatigue life prediction in a shorter test time. This approach not only reduces the test time but also reduces the carbon footprint in using the test resources.
Authors
Citation
Soma, N., sr, R., and Kadekodi, P., "Fatigue Life of a Rocker Arm Using Calibrated Accelerated Life Test Approach," SAE Technical Paper 2021-26-0453, 2021, https://doi.org/10.4271/2021-26-0453.Also In
References
- El Amraoui , A. , El Gharad , A. , and Ouadi Bensalah , M. On Stochastic Evaluation of SN Models Based on Lifetime Distribution Appl. Math. Sci 8 2014 1323 1331 http://dx.doi.org/10.12988/ams.2014.412
- Dixon , W.J. The Up-and-Down Method for Small Samples Journal of the American Statistical Association 60 312 1965 967 978 10.1080/01621459.1965.10480843
- Yoshimoto , I. Fatigue Test by Staircase Method with Small Samples Bulletin of JSME 5 18 1962 211 221 https://doi.org/10.1299/jsme1958.5.211
- Lai , T.L. Sequential Analysis: Some Classical Problems and New Challenges Statistica Sinica 2001 303 351 https://www.jstor.org/stable/24306854
- Pace , N.L. , Stylianou , M.P. , and Warltier , D.C. Advances in and Limitations of Up-and-Down Methodology: A Precis of Clinical Use, Study Design, and Dose Estimation in Anesthesia Research Anesthesiology 107 1 2007 144 152 10.1097/01.anes.0000267514.42592.2a
- Strzelecki , P. , Sempruch , J. , and Tomaszewski , T. Analysis of Selected Mathematical Models of High-Cycle SN Characteristics Technical Sciences 20 3 2017 227 240 https://doi.org/10.31648/ts.5424
- Pollak , R.D. Analysis of Methods for Determining High Cycle Fatigue Strength of a Material with Investigation of Ti-6Al-4V Gigacycle Fatigue Behavior Air Force Inst of Tech Wright-Patterson AFB OH School of Engineering and Management 2005