中文摘要：

为更精确地模拟钛合金的切削过程,将断裂力学的裂纹扩展能量理论作为材料损伤演化准则引入切削仿真,考虑刀具切屑接触面上的极限剪切应力随摩擦系数变化、摩擦系数随温度变化,建立了钛合金Ti-6Al-4V二维正交热力耦合切削仿真模型。通过钛合金车削试验及切屑金相观察试验对有限元模型进行验证,结果表明仿真的切削力、锯齿切屑形态与实验结果吻合程度较高。以该有限元模型为基础,分析了已加工表面的残余应力,预测了前角对切屑卷曲与损伤程度、剪切角、锯齿形状、刀具温度的影响。

英文摘要：

A two-dimensional orthogonal thermo-mechanical coupling a cutting model of Ti-6Al-4V is developed to precisely model the cutting process of titanium alloy. The crack extending energy theory in fracture mechanics is integrated into cutting simulation to act as material damage evolution criteria. The ultimate shear stress in tool and chip interface is considered to change with coefficient of friction, in which the coefficient of friction is also treated to a function of temperature. The finite element model is validated through turning experiment and chip metallographic observation experiment. The results show that simulation cutting force and segmented chip morphology well coincide with the experimental. The machining surface residual stress is analyzed. The effect of rake angle on chip damage degree, morphology, shear angle, tool temperature is predicted based on the validated model.