缺口件p-S-N曲线的随机有限元法与试验应用

SFEM for p-S-N Curve of Notched Specimens and Test Application

  • 摘要: p-S-N曲线是结构疲劳可靠性分析的重要依据之一,获取最可靠的p-S-N曲线的方法是基于试验数据。由于耗时长,缺口形式多变等原因,缺口件p-S-N曲线往往难以全部通过试验获得。使用随机有限元法(stochastic finite element method,SFEM)计算疲劳寿命与疲劳强度得到了一定研究,但参数常常比较复杂。考虑光滑件p-S-N曲线和缺口几何参数,使用随机有限元法模拟缺口分散性,与表示光滑件疲劳寿命分散性的p-S-N曲线结合起来,通过蒙特卡洛抽样得到相应的局部应力应变的随机样本,获取了缺口件的p-S-N曲线,并将其用于疲劳可靠性研究的一部分,低载删除的试验研究。试验表明该方法可行,可以用于缺口件p-S-N曲线的拟合折算。

     

    Abstract: The p-S-N curve is one of the most important basis of fatigue reliability analysis, and the test approach is the most reliable method to obtain p-S-N curve. Due to the long time, the variety of the notch form and other reasons, the p-S-N curve of notched specimens is often difficult to get by means of test. Calculating the fatigue life and fatigue strength is studied by using the stochastic finite element method(SFEM), but the parameters are often complex. Considering the p-S-N curve of smooth specimens and the notch geometry parameters, Dispersion of stress and strain caused by notch dispersion is combined with the p-S-N curve that indicate fatigue life dispersion by stochastic finite element method. The p-S-N curve of the notched specimens is obtained by Monte Carlo sampling, and is used for part of the study of fatigue reliability, experimental study on small load omitting. The experimental results show that the approach is feasible and can be used to fit the p-S-N curve of notched specimens.

     

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