一种针对铆接结构进行疲劳寿命评估的新方法

提出了一种针对铆接结构进行疲劳寿命评估的新方法。首先,运用弹塑性理论模型求解出铆接造成的铆钉孔周边的残余应力。然后,通过三维弹塑性、接触非线性有限元分析(Finite element method,FEM),计算出载荷传递引起的铆钉孔周围的应力分布。将这两个应力场进行叠加,并将沿径向距离疲劳危险部位应力最大处特定距离的点的应力,对照相关材料的光滑试件S-N曲线进行插值,得到疲劳寿命的评估结果。新方法与应力严重系数法(Stress severity factor,SSF)法进行了对比,并通过试验验证了该方法的可行性和准确性。

New Method of Fatigue Life Prediction for Riveted Structure

A new method of fatigue life prediction for riveted structure is presented. Elastic-plastic theoretical model is used to obtain the distribution of riveted residual stress around riveted hole, and the distribution of stress around riveted hole caused by loading transferring is calculated by 3-D elastic-plastic contact nonlinear finite element method(FEM). The above two stress fields are superimposed. According to the stress value of the point with a certain distance along the radial direction from the fatigue dangerous position where the stress is maximum, the fatigue life prediction is carried out by interpolating the S-N curve of smooth specimen of the referred material. The new method is compared with the stress severity factor (SSF) method, and feasibility and accuracy of the new method are proved by experiments.