基于应变梯度的微切削第一变形区几何分析模型的研究

Size of Primary Shear Zone in Micro-cutting Based Strain Gradient Theory

应用应变梯度塑性理论构建了微切削第一变形区的力学模型,在此力学模型的基础上提出了第一变形区几何尺寸的分析预测方法和影响因素,得出当材料的内禀长度l越小,即材料相对均匀时,第一变形区厚度赿小.当切削厚度增大时,第一变形区的长度增大.设计了正交切削实验来验证模型的有效性,实验结果表明随着进给量的增大,第一变形区厚度减小而第一变形区的长度反而增大.

Mechanical model of primary shear zone in micro-cutting was developed based on the strain gradient plasticity theory,and method for prediction the size of primary shear zone was proposed on the developed model.The model shows the thickness of the primary deformation zone decreases when the intrinsic length scale decreases,that is the micro structure is more homogeneous.When the uncut chip thickness is larger,the length of the primary deformation zone increases.The orthogonal micro-cutting experiments were carried out to validate the proposed model.The results show the thickness of the primary deformation zone decreases when the feed rate increases,while the length of the primary deformation zone increases.