INTERVAL ESTIMATION FOR STRUCTURAL FATIGUE LIFETIME
结构疲劳寿命的区间估计

Fatigue lifetime of structure with uncertainties in material properties and external loading is estimated. Fatigue lifetime of structure, in general, is the function of these uncertain factors. Based on interval mathematics, modeling these uncertainties as interval numbers, a new method, which approximately estimates the fatigue lifetime with the help of first-order Taylor series, is presented. Interval analysis method overcomes the shortcoming that probabilistic analysis method needs a large number of prior statistical data, and it need less computational efforts than the latter. Typical numerical examples are used to illustrate that under small uncertain degree condition the interval analysis method can provide sufficient accuracy as probabilistic method for any kinds of lifetime functions, including linear or nonlinear.