Abstract
In the present investigation the characteristic fatigue life prediction of A 356.2 T6 aluminum alloy has been statistically analyzed by log normal distribution. Fatigue tests were conducted on aluminum alloy specimen on rotary bending fatigue testing machine at six different stress levels. A step wise procedure is outlined to determine the number of specimen required at predetermined stress amplitudes. Details of generation of S-N curve for A 356.2 T6 aluminum alloy using a regression analysis is delineated. ANOVA is performed in order to check the significance of regression equation. The adequate sample size required for evaluating the average fatigue life of A 356.2 T6 with an acceptable error at 50 % probability and 90 % confidence level using log normal distribution is established from this study. The experimental results are presented in the form of R-S-N curves, which are helpful for designers.
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Abbreviations
- s:
-
standard deviation of log fatigue life
- \(\bar x\) :
-
sample mean of log fatigue life
- t:
-
student ‘t’ value
- n:
-
sample size
- u:
-
normal deviate
- N:
-
Average Fatigue Log life in Cycles
References
Lipson, C. and Sheth, N. J., “Statistical design and analysis of engineering experiments,” McGraw-Hill Kogakusha Ltd., 1973.
Luko, S. N., “A review of the weibull distribution and selected engineering applications,” SAE Paper, No. 1999-01-2859, 1999.
Belmonte, H. M. S., Mulheron, M., Smith, P. A., Ham, A., Wescombe, K. and Whiter, J., “Weibull-based methodologies for condition assessment of cast iron water mains and its application,” Fatigue Fract. Eng. Mater. Struct., Vol. 31, No. 5, pp. 370–385, 2008.
Khandaker, M. P. H., Ekwaro-Osire, S. and Gautam, K., “Applying modified Weibull failure theory to biomaterial specimen under thermal loading,” Fatigue Fract. Eng. Mater. Struct., Vol. 31, No. 3–4, pp. 281–294, 2008.
Gope, P. C., “A method for sample size determination to estimate average fatigue life,” Proc. of IX ISME Conference on Mechanical Engineering, pp. 497–501, 1994.
Parida, N., Das, S. K., Gope, P. C. and Mohanty, O. N., “Probability, confidence, and sample size in fatigue Testing,” J. Testing and Evaluation, Vol. 18, No. 6, pp. 385–389, 1990.
Nakazawa, H. and Kodama, S., “Statistical research on fatigue and fracture,” Current Japanese Materials Research, Vol. 2, pp. 59–69, 1987.
Gao, Z., “The confidence level and determination of minimum specimens and fatigue testing,” International Conference Fatigue and Fatigue Threshold, pp. 1203–1211, 1984.
ASTM STP 9, “A guide for fatigue testing and the statistical analysis of fatigue data,” 1963.
Gope, P. C., “Determination of minimum number of specimens in S-N testing,” J. Eng. Mater. Technol., Vol. 124, No. 4, pp. 421–428, 2002.
Gope, P. C., “Determination of sample size for estimation of fatigue life by using Weibull or log-normal distribution,” Int. J. Fatigue, Vol. 21, No. 8, pp. 745–752, 1999.
Lawless, J. F., “On the estimation of safe life when the underlying life distribution is weibull,” Technometrics, Vol. 15, No. 4, pp. 857–865, 1973.
Wilks, S. S., “Determination of sample size for setting tolerance limits,” Annals of Mathematical Statistics, Vol. 12, No. 1, pp. 91–96, 1941.
Ramamurty Raju, P., Satyanarayana, B., Ramji, K. and Suresh Babu, K., “Evaluation of fatigue life of aluminum alloy wheels under radial loads,” Eng. Failure Anal., Vol. 14, No. 5, pp. 791–800, 2007.
Zhao, Y.-X., Gao, Q. and Sun, X.-F., “A statistical investigation of the fatigue lives of Q235 steel-welded joints,” Fatigue Fract. Eng. Mater. Struct., Vol. 21, No. 7, pp. 781–790, 1998.
Schijve, J., “Statistical distribution functions and fatigue of structures,” Int. J. Fatigue, Vol. 27, No. 9, pp. 1031–1039, 2005.
Bureau of Indian Standards (BIS), Govt. of India, “Method of rotating bar bending fatigue testing of metals,” IS 5075, 1985.
Ramamurty Raju, P., Satyanarayana, B. and Ramji, K., “Sample size determination for development of S-N curve of A356.2-T6 aluminum alloy,” Structural Durability and Health Monitoring, Vol. 4, No. 3, pp. 161–171, 2008.
Little, R. E. and Jebe, E. H., “Statistical design of Fatigue experiments,” Applied Science Publishers Ltd., 1975.
Ravi, S., Balasubramanian, V., Babu, S. and Nemat Nasser, S., “Influences of MMR, PWHT and notch location on fatigue life HSLA steel welds,” Engineering Failure Analysis, Vol. 11, No. 4, pp. 619–634, 2004.
Balasubramanian, V., Guha, B., Swamindas, A. S. J. and Seshadri, R., “Influences of sheileded metal arc welded cruciform joint dimensions on toe crack failures of pressure vessel grade steels,” Engineering Failure Analysis, Vol. 7, No. 3, pp. 169–179, 2000.
Mahagaonkar, S. B., Brahmankar, P. K. and Seemikeri, C. Y., “Effect on fatigue performance of shot peened components: An analysis using DOE technique,” International Journal of Fatigue, Vol. 31, No. 4, pp. 693–702, 2009.
Golinkin, I. A., Ruff, D. D., Kvam, E. P., McCabe, G. P. and Grandt, A. F., “Application of analysis of variance (ANOVA) statistical methods to breaking load corrosion test,” J. Test. Eval., Vol. 25, No. 6, pp. 565–570, 1997.
Naikan, V. N. A., “Reliability Engineering and Life Testing,” PHI Learning Private Limited, 2009.
Achutha, M. V., Sridhara, B. K. and Abdul Budan, D., “A reliability based stress-life evaluation of aluminium-graphite particulate composites,” Materials and Design, Vol. 29, No. 4, pp. 769–774, 2008.
Park, T. G., Choi, C. H., Won, J. H. and Choi, J. H., “An efficient method for fatigue reliability analysis accounting for scatter of fatigue test data,” Int. J. Precis. Eng. Manuf., Vol. 11, No. 3, pp. 429–437, 2010.
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Raju, P.R.M., Rajesh, S., Satyanarayana, B. et al. Evaluation of stress life of aluminum alloy using reliability based approach. Int. J. Precis. Eng. Manuf. 13, 395–400 (2012). https://doi.org/10.1007/s12541-012-0050-2
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DOI: https://doi.org/10.1007/s12541-012-0050-2