Development of Virtual Microscope Based on Renormalization Group Molecular Dyanamics and Its Application to Machining Process Observation

重整化群分子动力学已经被提出来模拟从纳米到微米的各种尺度的物理现象。该方法不仅可以单独处理各种尺度，而且可以组合处理各种尺度，从而可以在宏观尺度模拟结果的基础上，通过重新进行局部缩放模拟来分析仅发生在宏观尺度场中的微观尺度现象。然后，该方法被用来分析如何缺陷可以形成在单晶硅加工时。研究表明，该机制是静、动态相结合的，即局部不稳定的静应力状态引起的微剪切，是由声波引起的动态重复拉压作用引起的。该事件然后在工具的浮雕面下方的晶体结构中产生具有弱化的材料性质的非晶区，并且再次通过与穿过该区域的声波相关联的动态拉伸应力导致在那里形成微裂纹状缺陷。

Renormalization group molecular dynamics has been proposed to simulate physical phenomena in various scales ranging from nanometer to micrometer. The method can handle various scales not only in separate manner but also in combined manner such that microscale phenomena which occur only in macroscale field can be analyzed by re-doing locally zoomed simulation based on results in macroscale simulation. The method is then used to analyze how defects can be formed in a monocrysytal silicon when it is machined. The mechanism which has been made clear is combined static/dynamic one such that a locally unstable static stress state causes micro shearing trigged by dyanamically repeated tensile/compressive action caused by acoustic wave. This event then creates amorphous zone with weakened material property in crystal structure under the relief face of a tool and leads to formation of a microcrack-like defect there, again by dynamic tensile stress associated with acoustic wave passing through the region.