Weak ternary interval evaluation of fatigue life and its application to mining dump truck

Abstract

A method of weak ternary interval (TI) evaluation of fatigue life is proposed in this study to reasonably evaluate the nonprobabilistic reliability considering the interval uncertainty. The conventional interval is extended into a TI by introducing an expected value, that is, a value without uncertainty, as the third parameter of the interval to deal with the deviation between the expected value and the median value of the interval. Next, the TI of fatigue life is evaluated by introducing an index of attitude in the exponential function to weaken the unimportant upper bound and deal with the overconservative lower bound. Therefore, the evaluation is reflected in the form of an equivalent fatigue life as an indicator of the nonprobabilistic reliability. Next, the TIs of the fatigue parameters are obtained with limited fatigue test data from a practical engineering application. Finally, the proposed method is applied to a mining dump truck frame to demonstrate its significance and validity.