一种面向非共格性界面的分级式多尺度力学模型及应用

项目名称： 一种面向非共格性界面的分级式多尺度力学模型及应用

项目编号： No.11472079

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 数理科学和化学

项目作者： 糜长稳

作者单位： 东南大学

项目金额： 75万元

中文摘要： 在力学范畴内固体界面效应是指界面自由能、界面应力与力学响应性能对复合材料的宏细观力学行为的影响和修正，其思路是研究由引入界面相所诱发的空间尺度依赖关系。本项目拟运用细观力学、分子力学和分级式多尺度框架等现代力学理论与计算方法研究非共格性界面效应分析中几个具体的关键问题，围绕界面的热力学和力学响应特性在细观和纳观尺度下的合理表征，揭示固体间界面特性在纳观尺度下的物理根源，进而探讨其在细纳观尺度下的关联和耦合，完备细观尺度中组建的非共格性界面力学模型。再与经典细观力学理论体系通过一般曲线坐标中的曲面和空间映射分析实现耦合，建立以界面力学效应分析为中心的分级式跨细纳观尺度计算力学理论和方法，并应用于一类具有明确解的经典细观力学问题的界面力学效应研究中。项目研究目标的实现将增加纳米复合材料宏细观力学性能对增强体与基底之间的界面基本热力学参数和力学响应性能依赖关系的理解。

中文关键词： 尺度效应；表面效应；分子动力学模拟；多尺度模拟；细观力学

英文摘要： Within the context of solid mechanics, the effects of a solid-solid interface represent the impact of interfacial free energy, interfacial stress, and interfacial mechanical responses on the overall mechanical behavior of composites at both micro- and macro-scales. The focus is often placed on a length-scale dependence naturally introduced by the inclusion of the interfacial phase. The research objective of this project is to establish an incoherent interface-oriented hierarchical model on computational nanomechanics. Several modern mechanical theories including molecular mechanics, classical micromechanics of defects in solids, as well as a hierarchical multiscale configuration are employed to tackle a few critical problems necessary for the analysis. Rational characterization of the property of solid-solid interfaces at micro and nano-scale is the first step. The physical origin of the influential effects of solid-solid interfaces is explored in great detail at nanoscale. Subsequently, the characterization parameters of interface properties at both scales are correlated and coupled to perfect the interfacial constitutive relationship at the microscale. This condition, together with the deformation configuration and three-phase force balance condition across the interface, form a complete description of interface modeling. An incoherent interface-oriented hierarchical model on micro and nanomechanics of defects in solids can now be seamlessly constructed by the coupling of these field equations uniquely designed for interfaces and those classical ones for bulk phases. The proposed model is to be validated by its application on a few classical micromechanical problems with deterministic solutions. It possesses optimistic potentials for better understanding the influential effects of interfaces originated from particle-substrate boundaries and provides useful guidelines for the artificial design of nanocomposites.

英文关键词： Size effect;Surface effect;Molecular Dynamics Simulation;Multi-scale simulation;Micromechanics