微动疲劳结构应力强度因子有限元分析

 采用ABAQUS软件建立了铝合金的圆柱/平面接触微动疲劳结构有限元全局模型和子模型,运用该模型将计算的应力值与解析解进行比较,结果相当吻合,证明了本文有限元模型及方法的有效性。最后在FRANC2D/L中用接触区的正应力和剪应力代替压头,重建子模型。通过分析得到了不同影响因素下应力强度因子（SIF）随裂纹扩展历程变化规律的曲线。结果表明,外加循环应力是影响SIF的最主要因素,SIF随循环应力的增加而增加。在微动疲劳影响深度区内,SIF随接触压力P、摩擦因数f以及Q/(fP)（Q为切向力）的增加而增加。Q/(fP)的影响最大,摩擦因数的影响最小，接触压力介于二者之间;超过该深度,SIF对其不再敏感。

Finite Element Analysis of Stress Intensity Factors of Fretting Fatigue Structure

A global finite element model and sub-model of fretting fatigue of alumium alloy column and plan contact is performed using the commercial code ABAQUS. The effectiveness of the model is validated through a comparison of analytical solution and numerical solution. In the reconstruction of the sub-model with the fracture mechanics code FRANC2D/L, the fretting pad portion is substituted by its equivalent stresses in contact region, which include the normal stress and shear stress. Stress intensity factors (SIFs) are obtained for different influence factors. The results show that cyclic bulk stress has a dominant effect on SIF, which increases as the cyclic bulk stress amplitude increases. Within the depth affected by fretting fatigue, SIF increases as the values of the parameters (the contact load P , the friction coefficient f and the ratio Q/(fP) , where Q is tangential stress) increase. Of these parameters, the ratio Q/(fP) has the most significant effect on SIF, followed by the contact load P , while the coefficient of friction f has the least effect on SIF. Beyond this depth affected by fretting fatigue, these parameters have relatively little effect on SIF.