结构疲劳寿命的区间估计

对材料性质和载荷具有不确定性的结构进行了疲劳寿命估计．结构的疲劳寿命往往是这些不确定性因素的函数．以区间数学为基础，将这些不确定性因素用区间进行定量化，借助一阶Taylor级数，提出了近似估计结构疲劳寿命的区间分析方法．区间分析方法克服了概率分析方法需要预先知道大量统计数据的缺点，且计算量小．通过典型数值算例将区间分析方法和概率分析方法进行了比较，结果表明了区间分析方法对线性和非线性形式的结构寿命估计在小不确定度情况下均能提供足够的精度．

INTERVAL ESTIMATION FOR STRUCTURAL FATIGUE LIFETIME

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.