微纳米多层材料的断裂力学-非局部效应和表面/界面效应的连续介质统一模型

This project develops an upgraded finite element method and establishes various fracture mechanics models for the simulation and analysis of micro/nanoscale multilayers. The novel improvement of the current method over the conventional finite element method is that it includes the nonlocal effect and the surface/interface forces of materials at micro/nanoscale simultaneously. This breaks through the disadvantages of the traditional continuum finite element method which can not consider the scale effect of the materials and the limitation of the atomic method which is computationally intensive. The proposed numerical technique also overcomes the difficulties of the existing multiscale methods in the simulation of micro/nanoscale multilayers. The project will provide new basic knowledge for the relationship between structure and failure mechanism of the micro/nanoscale multilayers, through extensive theoretical analysis and numerical simulations. The project challenges many scientific issues among the mechanics of composite materials, fracture mechanics and computational solid mechanics. It will greatly enhance the current understanding of the fracture behavior of micro/nanoscale multilayers as well as many types of nonhomogeneous, multi-phase material systems in modern science and technology.

将材料的非局部效应、表面效应和界面效应统一引入到微纳米多层材料的力学分析中，构造一种新型、升级的有限元数值方法以及断裂力学分析模型。所提出的数值方法克服了传统的连续介质有限元方法不能考虑材料尺度效应的缺点，突破了原子模拟方法在计算规模上的局限性，也解决了现有的多尺度方法在模拟多层材料时遇到的特征长度不匹配的困难。通过对微纳米多层材料进行断裂力学数值模拟和理论分析，掌握这类材料破坏行为的一些基本规律，加深对这类材料失效机制的理解。本项目首次将材料的非局部效应和表面/界面效应同时引入到微纳米多层材料的断裂力学研究，涉及复合材料力学、断裂力学和计算固体力学的前沿、热点问题，面临许多挑战，如能成功实施，将摆脱人们对微纳米多层材料断裂行为认识的许多限制，对完善现代科学技术中的多层、多相材料系统的力学性能评价和可靠性设计具有重要的理论意义。

本项目将材料的非局部效应、表面效应和界面效应统一引入到微纳米多层材料的力学分析中，构造一种新型、升级的有限元数值方法以及断裂力学分析模型。所提出的数值方法克服了传统连续介质有限元方法不能考虑材料尺度效应的缺点，突破了原子模拟方法在计算规模上的局限性，也解决了现有的多尺度方法在模拟多层材料时遇到的特征长度不匹配的困难。通过对微纳米多层材料进行断裂力学数值模拟和理论分析，掌握了这类材料破坏行为的一些基本规律，加深了对这类材料失效机制的理解。本项目首次将材料的非局部效应和表面/ 界面效应同时引入到微纳米多层材料的断裂力学研究，涉及复合材料力学、断裂力学和计算固体力学的前沿、热点问题，摆脱了人们对微纳米多层材料断裂行为认识的许多限制，对完善现代科学技术中的多层、多相材料系统的力学性能评价和可靠性设计具有重要的理论意义。