ITR/ASE-SIM: Multiscale Treatment of Systems with Strong Heterogeneities: Development of Hybrid Atomistic-Coarse-Grained Methodology and Computer Code

ITR/ASE-SIM：具有强异质性的系统的多尺度处理：混合原子粗粒度方法和计算机代码的开发

• 批准号: 0427746
• 负责人: Xiao Cheng Zeng
• 金额: $ 71.51万
• 依托单位: University of Nebraska-Lincoln
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-09-01 至 2009-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0427746&HistoricalAwards=false
• 关键词: ITR; ASE; SIM; Multiscale; Treatment

Xiao Zeng, Dennis Diestler, and Ruqiang Feng of the University of Nebraska are supported by the Chemistry Division under the Information Technology Research program to develop a hybrid atomistic-coarse-grained computational methodology capable of describing multi-scale processes. Ruben Parra of DePaul University will also participate as a summer visiting scholar. The prototypical system consists of two planar solid substrates separated at the interface by a fluid film. In the vicinity of the interface, atoms can execute irregular, large-amplitude motions whereas far regions of the substrates are homogenously strained. The fluid and near regions are treated atomistically while the far regions are described by continuum mechanics as a coarse-grain mesh. Thermomechanical properties are computed at ensemble averages, which are effected by Monte Carlo simulation. The expected outcome of this research is a powerful computational technique for analyzing the thermomechanical response of realistic fluid-solid and solid-solid interfacial systems, in which the coupling of the molecularly heterogeneous interface to the macroscopic continuum plays as essential role. Although the specific formulations will be cast with the contexts of thin-film lubrication and nanoindentation, the approach is applicable to other real-world physical problems such as crack propagation.

内布拉斯加州大学的肖曾、丹尼斯·迪斯特勒和冯如强在信息技术研究计划下的化学部的支持下，开发了一种能够描述多尺度过程的原子-粗粒度混合计算方法。德保罗大学的鲁本·帕拉也将以暑期访问学者的身份参加。原型系统由两个在界面处被流体膜隔开的平面固体衬底组成。在界面附近，原子可以进行不规则的大幅度运动，而衬底的远端区域是均匀应变的。流体和近区被原子化处理，而远区被连续介质力学描述为粗颗粒网格。热力性质的计算采用系综平均，受蒙特卡罗模拟的影响。这项研究的预期结果是一种分析现实流体-固体和固体-固体界面系统热机械响应的强大计算技术，其中分子非均质界面与宏观连续介质的耦合起着至关重要的作用。虽然具体的配方将在薄膜润滑和纳米压痕的背景下铸造，但该方法适用于其他真实世界的物理问题，如裂纹扩展。