变幅多轴疲劳寿命分析方法对比

Comparative study of variable amplitude multiaxial fatigue life analysis methods

基于当前对变幅多轴疲劳的研究,首先简要回顾了3种常用的变幅多轴疲劳寿命分析方法,包括Bannantine-Socie方法、Wang-Brown方法及王雷-王德俊方法。之后介绍了3种方法在程序中实现的具体方式,并对3种方法进行了编程实现。最后采用以上3种方法对飞机某结构危险部位在飞机服役过程中所承受的应力(应变)谱进行了分析,得到了3种方法的预测寿命。此外,为了比较多轴疲劳载荷对该结构寿命的影响,采用单轴的MansonCoffin方程对该结构进行了寿命分析。通过对各方法的寿命分析结果对比分析,Wang-Brown方法的预测结果比较合理,王雷-王德俊方法的预测结果偏保守,Bannantine-Socie方法的预测结果较其他2类方法偏大,而单轴疲劳寿命分析方法会给出较为危险的预测结果。

Three commonly used variable amplitude multiaxial fatigue life analysis methods,including Bannantine-Socie method,Wang-Brown method and Wang L-Wang D J method are reviewed briefly based on the current researches on variable amplitude multiaxial fatigue. Then,the algorithms of the three methods were introduced and calculated codes were written. Finally,the fatigue life of an aircraft structural component,which is subjected to complex variable amplitude multiaxial stress state during their service,was evaluated using the three multiaxial fatigue life analysis methods. In addition,uniaxial fatigue life was analyzed using the Manson-Coffin equation to compare the effect of multiaxial fatigue loading on the fatigue life of the structure.The comparison results are as follows： the estimated result of Wang-Brown method is reasonable,the Wang L-Wang D J method gives a conservative prediction result,the prediction result of Bannantine-Socie method is greater than that of the other two methods,while the uniaxial fatigue life analysis method gives more dangerous prediction result.