Optimal S-N Testing for Variable-Amplitude Fatigue Applications
Publication: Journal of Structural Engineering
Volume 129, Issue 6
Abstract
A new methodology is developed that can identify the optimal testing procedure to be used in generating S-N curves for predicting damage accumulation under variable-amplitude service loads. This is a significant extension of existing knowledge, which includes a solution to this problem only for situations in which the service loads are constant amplitude. The methodology has the potential to improve significantly the predictions of fatigue damage and reliability under realistic service loads. In general, finding the truly optimal solution involves solving a quartic equation, but it is often possible to use a simplified form that involves only a quadratic equation. The new results are identical to the previously developed formulation for the special situation of a constant-amplitude service load. The information needed to use the general procedure is the distribution of stress amplitudes in the service load and the variability of the service life among identical load/specimen combinations. The procedure is illustrated here by its application to the special case of bilevel service loads, for which numerical results are presented. This includes information on both the optimal S-N testing procedure, and the sensitivity of the mean-squared error to changes in the testing procedure.
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References
Benjamin, J., and Cornell, A. (1970). Probability, statistics, and decision for civil engineers, McGraw-Hill, New York.
Fisher, J. W., Mertz, D. R., and Zhong, A. (1983). “Steel bridge members under variable amplitude long life fatigue loading.” Rep. No. 267, National Cooperative Highway Research Program, National Academic Press, Washington, D.C.
Fisher, J. W., Nussbaumer, A., Keating, P. B., and Yen, B. T. (1993). “Resistance of welded details under variable amplitude long life fatigue loading.” Rep. No. 354, National Cooperative Highway Research Program, National Academic Press, Washington, D.C.
Lutes, L. D., and Sarkani, S. (1997). Stochastic analysis of structural and mechanical vibrations, Prentice-Hall, Englewood Cliffs, N.J.
Nelson, W. (1990). Accelerated testing: Statistical models, test plans and data analysis, Wiley, New York.
Information & Authors
Information
Published In
Journal of Structural Engineering
Volume 129 • Issue 6 • June 2003
Pages: 829 - 837
Copyright
Copyright © 2003 American Society of Civil Engineers.
History
Received: Nov 15, 2001
Accepted: Aug 13, 2002
Published online: May 15, 2003
Published in print: Jun 2003
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