Construction of virtual machining system for interrupted ultra-high speed machining

超高速加工作为先进加工系统的关键技术正在登上舞台。为了发展这项技术，实验研究人员正在尝试使用新设计的高速加工机床。然而，由于该机床的建造需要花费巨大的资金和时间，而且所选择的切割条件也是有限的，本研究试图在数字计算机上构建螺旋铣刀切割过程的仿真系统。在螺旋铣削加工中，未变形的切屑厚度随刀具旋转而变化，从而以三维方式生成切屑。采用三维弹塑性有限元方法，开发了螺旋铣刀加工过程的仿真系统。通过开发的系统可以清楚地显示刀具几何形状对切屑形成过程及其几何形状的影响，以及切削力及其变化的影响，由于铣削过程是以中断的方式进行的，冲击力的影响在过程中可以忽略不计。为了将该系统扩展到超高速加工领域，通过对超高速粒子与平板碰撞过程的仿真，对系统的动态响应进行了分析。在分析中，采用粘弹塑性单元建立了材料的力学性能模型。在实验数据的基础上，提出了模型中材料常数的确定方法。

An ultra high speed machining is coming on a stage as the key technology for an advanced machining system. in order to develop the technology, the experimental researchs are trying using the newly designed machine tool with high cutting speed. However, for construction of the machine, tool the huge expense is reqiured on money and time, and the cutting condition to be selected is also limited.In this research the simulation system on cutting process by a helical milling cutter was tried to construct in a digital computer. In helical milling machining, undeformed chip thickness changes with cutter rotation, and a chip is generated in three dimensional manner. The simulation system on cutting process by helical milling cutter was developed using the three dimensional Elastic- Plastic Finite Element Method. Through the developed system the effects of tool geometry on chip formation process and its geometry and on cutting forces and its change were clearly shown.Since milling process has interrupted manner, the effect of impact force may be negligible in the process. In order to expand the system to ultra-high speed machining, the dynamic response analysis was discussed through simulation on collision process of an ultra-high speed particle against a plate. In the analysis a model of mechanical property of material was proposed with visco-elasto-plastic elements. And the method for determination of material constants in the model was proposed based on the experimental data.