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建立了AISI 4340微细侧铣的二维有限元模型。将Johnson-Cook本构模型与JohnsonCook剪切失效模型相结合,对铣削刃旋转过程中的一个完整侧铣周期进行了仿真。由于没有考虑尺寸效应的影响,所得到的流动应力值偏小。因此,建立了应变梯度塑性模型,并应用其预测了切屑的形成、冯米斯应力和温度场。仿真结果显示:微细侧铣过程中存在尺度效应,与Johnson-Cook本构模型相比,应变梯度塑性模型能够很好地描述微细侧铣过程中的尺寸效应。最后,将仿真结果与理论计算结果相比较,验证了所建模型的正确性。
A two-dimensional finite element model of AISI 4340 micro-side milling is established. The Johnson-Cook constitutive model is combined with the JohnsonCook shear failure model to simulate a complete side-milling cycle during the milling cutter revolution. Due to the size effect is not considered, the resulting flow stress value is small. Therefore, a strain gradient plastic model was established and used to predict chip formation, von Mises stress and temperature field. The simulation results show that there is scale effect in the micro side milling process. Compared with the Johnson-Cook constitutive model, the strain gradient plastic model can describe the size effect in the micro side milling process well. Finally, the simulation results are compared with the theoretical results to verify the correctness of the proposed model.