In traditional reliability problems, the distribution of a basic random variable is usually unimodal; in other words, the probability density of the basic random variable has only one peak. In real applications, some basic random variables may follow bimodal distributions with two peaks in their probability density. When binomial variables are involved, traditional reliability methods, such as the first-order second moment (FOSM) method and the first-order reliability method (FORM), will not be accurate. This study investigates the accuracy of using the saddlepoint approximation (SPA) for bimodal variables and then employs SPA-based reliability methods with first-order approximation to predict the reliability. A limit-state function is at first approximated with the first-order Taylor expansion so that it becomes a linear combination of the basic random variables, some of which are bimodally distributed. The SPA is then applied to estimate the reliability. Examples show that the SPA-based reliability methods are more accurate than FOSM and FORM.
Reliability Methods for Bimodal Distribution With First-Order Approximation1
Manuscript received November 5, 2017; final manuscript received April 15, 2018; published online August 14, 2018. Assoc. Editor: Alba Sofi.
- Views Icon Views
- Share Icon Share
- Cite Icon Cite
- Search Site
Hu, Z., and Du, X. (August 14, 2018). "Reliability Methods for Bimodal Distribution With First-Order Approximation." ASME. ASME J. Risk Uncertainty Part B. March 2019; 5(1): 011005. https://doi.org/10.1115/1.4040000
Download citation file:
- Ris (Zotero)
- Reference Manager