介观尺度切削过程的材料本构关系分析

应用应变梯度理论,建立了考虑尺度效应的介观切削材料本构关系;应用建立的本构关系对于不同切削条件时材料的应力-应变关系进行了分析研究。研究表明:随着切削厚度的增加,材料力学性能曲线逐渐向宏观Johnson-Cook(JC)模型靠近;当前角增大时,剪切角随之增大,材料内部的应力加大,材料的尺度效应越明显,因此适当增大刀具前角有利于介观尺度切削;切削刃半径对材料性能的影响比较明显,随着切削刃半径的减小,材料性能的尺度效应逐渐显著,要实现介观尺度切削,刀具切削刃半径必须极小。

Analysis on Constitutive Relation in Meso-scale Cutting Process

By using strain gradient theory,a material's constitutive relationship was formulated in the meso-scale cutting process.The constitutive relationship considering the size effect was constructed.Based on the relationship,the material's stress-strain was studied under different cutting conditions.The results show that the material behaviors is approached to Johnson-Cook(JC)model gradually with the increase of cutting depth;if the rake angle becomes large,the shear angle and internal stress of material increas...