薄壁件周铣切削力建模与表面误差预测方法研究

 薄壁件加工变形是影响加工精度与质量的关键因素,而切削力建模则是预测表面加工误差的基础。针对两种典型的切削力模型,系统地研究了薄壁件周铣加工过程中切削力变化及表面变形误差分布的有限元计算方法,提出了基于三维非规则网格的刀具/工件变形的耦合迭代格式以及恒定网格下材料去除效应的变刚度处理方法等关键技术,仿真过程充分考虑了切屑厚度变化及不同切削参数对预测结果的影响。以典型钛合金航空材料构件为例,数值计算结果与实验参考数据比较表明,两种切削力模型对同一切削过程的预测均具有很好的一致性。

Investigation on Cutting Force Modeling and Numerical Prediction of Surface Errors in Peripheral Milling of Thin-walled Workpiece

Cutting deformation is a key factor influencing the precision and quality of the machined thin-walled workpiece. A reasonable cutting force modeling constitutes the basis for the numerical prediction of surface errors. Based on two typical cutting force models, a finite element numerical simulation procedure is proposed to evaluate cutting forces and surface errors in peripheral milling of thin-walled workpiece. Some key techniques such as the iterative scheme for the calculations of tool-workpiece deflections with 3D irregular meshes and the modeling of material removal without remeshing in milling are proposed. Influences of the uncut chip thickness variation and different cutting coefficients upon the simulation results are fully taken into account. Based on the typical cutting case with Titanium alloy, numerical results obtained are compared with the existing experimental and simulation results. It is shown that both cutting force models have a good coherence for the same cutting process.