孔冷挤压有限元仿真中的铰削分界面位置确定方法

开展孔冷挤压过程有限元仿真计算是残余应力分布获取和疲劳寿命预测的前提。在有限元建模阶段，设置铰削层单元与基体材料单元之间的分界面，是模拟铰制终孔工艺过程的关键。通过弹塑性力学分析，建立了挤压强化过程芯棒、衬套和被挤压强化连接孔的应力分析方法；基于分析中得到的不同位置处微单元的径向位移量，建立了铰削分界面相对位置计算模型。并开展了关键参数的敏感性分析，定量研究了关键参数变化对残余应力分布和径向位移量的影响程度。本工作为孔冷挤压强化有限元模型建立中，铰削层单元与基体材料单元分界面相对位置确定，提供了便捷可靠的方法。

Determining position of reaming interface in cold expansion FEM simulation

The finite element simulation of split sleeve cold expansion process is the prerequisite for obtaining residual stress distribution and predicting fatigue life. In the finite element modeling stage, setting reaming interface between the reaming element layer and the matrix element is the key to simulate the reaming process of final hole. Through elastic-plastic mechanical analysis of cold expansion, a two-dimension residual stress and strain analysis method for mandrel, split sleeve and plate is established. Based on the radial displacement of micro-elements at different positions, a relative position calculation model of the reaming interface is established. Sensitivity analysis of key parameters is carried out to quantitatively study the influence of key parameters on residual stress distribution and radial displacement. For the finite element modeling of hole cold expansion process, this study provides a convenient and reliable method for determining the relative position of reaming interface between the reaming element layer and the matrix element.