A structural fatigue design by using random polynomials with wave coefficients

✍ Scribed by S. Rezakhah; A.R. Soltani

• Publisher: Elsevier Science
• Year: 2001
• Tongue: English
• Weight: 283 KB
• Volume: 47
• Category: Article
• ISSN: 0362-546X
• DOI: 10.1016/s0362-546x(01)00432-1

✦ Synopsis

Fatigue is considered as a primary model of failure for metallic structures or mechanical devices subjected to oscillatory stress processes. In this paper we consider certain random polynomials as the underlying stress processes, and recommend the evaluations of fatigue indices. Let (Q_{n}(x)=\sum_{i=0}^{n} A_{i} x^{i}), where (A_{j}:=\sum_{k=1}^{m} R_{k} \cos j \omega_{k}, j=) (1,2, \cdots, n), and (R_{1}, \cdots, R_{m}) are independent normally distributed random variables, (R_{k} \sim N\left(0, r_{k}^{2}\right), k=1,2, \cdots, m) and (\omega_{1}, \cdots, \omega_{m}) are given frequencies. We derive an explicit formula for the expected density of the number of real zeros of (Q_{n}(x)).