Chaotic Dynamics and Fractals in Material Removal Processes

该项目的目标之一是将在非线性动力学和分形领域中发现的知识应用于材料去除过程。特别是，该活动将侧重于材料切削动力学的物理学以及在机床中观察到的混沌振动与工件表面分形特性之间的关系。动态系统和分形中的现代实验、计算和分析方法将用于特定的机床系统，如车床切割和铣削。实验的主要目的是建立刀具动力学与表面质量之间的关系，特别是刀具运动中的混沌振动与表面光洁度中的分形或随机特性之间的关系。刀具动力学的非线性模型将进行分析和计算研究。这些模型将包括时间延迟或再生效应以及材料的非线性力在切割过程中。特别令人感兴趣的将是寻找共存的多个动力吸引子及其吸引盆地。实验上，目标是测量材料被移除时和后动态状态下的表面粗糙度。机床颤振是严重制约机床生产效率的重要现象。如果能更好地理解颤振过程，抑制不必要的振动将使机床能够以良好的表面光洁度进行更重的切削。

9313404 Moon One of the objectives of the project is to transfer knowledge discovered in the fields of nonlinear dynamics and fractals to applications in material removal processes. In particular, the activity will focus on the physics of material cutting dynamics and the relation between observed chaotic vibrations in machine tools and fractal properties of workpiece surfaces. Modern experimental, computational, and analytical methods in dynamical systems and fractals will be employed on particular machine tool systems such as lathe cutting and milling. The principal aim of the experiments will be to establish a correlation between cutting tool dynamics and surface quality, especially between chaotic vibrations in the tool motions and fractal or random like properties in the surface finish. Nonlinear models for cutting tool dynamics will be investigated both analytically and computationally. These models will incorporate both time delay or regenerative effects as well as material nonlinearity forces in the cutting process. Of particular interest will be the search for coexisting multiple dynamical attractors and their basins of attraction. Experimentally, the goal is to measure the surface roughness both as the material is being removed and in the post dynamics state. Chatter of machine tools is a critical phenomenon that severely limits their productivity. If the chatter process can be better understood, the suppression of unwanted vibration will allow machine tools to take heavier cuts with good surface finish.