Development of Simulation Software for Rapid and Reliable Simulations of Nanotribology

从环境保护、能源节约、空间机械的发展和小型化的要求等各个方面来看，微纳区域摩擦学现象的重要性日益增加。摩擦学现象通常是由接触界面上润滑油分子在极端压力下的微观行为引起的。为了研究这些现象，需要超越常规机械工程范围的原子或分子水平的研究方法。纳米摩擦学是从微观化学的角度来研究机械工程中的摩擦学现象的，为了建立一种研究摩擦学现象的方法，推动纳米摩擦学的发展至关重要。在这个研究项目中，分子模拟平台TRIBOSIM被用作澄清纳米摩擦学现象的技术种子，该平台是首席研究员之前研究活动的结果。我们开发了一种新的分子模拟方法，实现了纳米摩擦学现象的精确分析。我们还开发了一个量子化学分子动力学纳米摩擦学模拟器Tribo-Colors，用于澄清摩擦化学反应动力学。此外，我们还取得了重要的研究成果，即1)开发了确定润滑油分子初始构象的新方法，用于精确模拟；2)开发了粗粒度分子动力学方法，用于快速模拟。3)开发新的牵引力系数预测方法；4)开发用于定量预测的运动粘度模拟器。

The importance of tribology phenomena at micro or nano regions is increasing from the various aspects such as environmental conservation, energy saving, development of space machineries, and requirements for downsizing. Tribology phemena are generally caused by microscopic behaviors of lubricant molecules at the contacting interface under extreme pressures. In order to study such phenomena, research approaches at the atomistic or molecular level, which are beyond the scope of conventional mechanical engineering, are necessary. In order to create a methodology to clarify the tribology phenomena, it is essentially important to promote the nanotribology, which deals with the phenomena in the mechanical engineering from the microscopic perspectives of chemistry.In this research project, molecular simulation platform TRIBOSIM, which was developed as results of previous research activities by principal investigator, was used as the technology seed for the clarification of nanotribology phenomena. We have developed a novel molecular simulation method that realizes the accurate analyses of nanotribology phenomena. We have also developed a quantum chemical molecular dynamics nanotribology simulator Tribo-Colors for the clarification of tribochemical reaction dynamics. Furthermore, we succeeded in obtaining siginificant research results, i.e. 1)development of novel method to determine initial conformation of lubricant molecules for accurate simulations, 2)development of coarse-grained molecular dynamics method for rapid simulations. 3)development of novel method for traction coefficient predictions, and 4)development of kinematic viscosity simulator for quantitative viscosity predictions.