Reliability Estimation for Structure under Fatigue Load Using Probability Theory and Fatigue Crack Growth Model

초록

Methodologies to calculate the failure probability and to estimate the reliability of the damaged structures under fatigue are developed in the present work. The applicability of the developed methodologies is evaluated with the help of fatigue crack growth models suggested by Paris and Walker. Probability theories such as the FORM (first order reliability method) and the SORM (second order reliability method) are utilized for the seven cases. It is found that the failure probability increases with the increase of the initial fatigue crack size and the decrease of the design fatigue life. It is also found that the failure probability calculated by the FORM and the SORM turns out similar for the Paris and the Walker models. And the distribution types of the slope of the Paris equation and the coefficient of the Paris equation dominantly affect the failure probability.