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.

中文翻译：

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疲劳寿命的弱三元区间评估及其在自卸车中的应用

提出了一种疲劳寿命的弱三元间隔（TI）评估方法，以合理地评估考虑间隔不确定性的非概率可靠性。通过引入期望值即没有不确定性的值作为间隔的第三参数来处理间隔的期望值和中间值之间的偏差，从而将常规间隔扩展为TI。接下来，通过在指数函数中引入态度指数来评估疲劳寿命的TI，以削弱不重要的上限并处理过度保守的下限。因此，评估以等效疲劳寿命的形式反映出来，作为非概率可靠性的指标。下一个，疲劳参数的TI是通过实际工程应用中有限的疲劳测试数据获得的。最后，将所提出的方法应用于矿用自卸车车架，以证明其重要性和有效性。