颗粒材料渐进破坏过程的细观结构演化与机理研究

项目名称： 颗粒材料渐进破坏过程的细观结构演化与机理研究

项目编号： No.11272069

项目类型： 面上项目

立项/批准年度： 2013

项目学科： 数理科学和化学

项目作者： 秦建敏

作者单位： 大连大学

项目金额： 72万元

中文摘要： 颗粒材料渐进破坏一直是岩土工程领域中的经典问题。为揭示颗粒材料在渐进破坏过程中所呈现的变形局部化、相变及破坏机制，本研究将借助微细观力学实验和离散元数值分析、物理分析等手段，开展微-细-宏观相结合的多尺度分析。为完整描述以变形局部化为特征的破坏过程中，颗粒材料的微观受力、细观变形以及颗粒体系的宏观力学响应，本项目以孔隙胞元作为中间尺度，构建"颗粒接触对-孔隙胞元-颗粒体系"的"微-细-宏"多尺度框架，建立各尺度层次上参数间的联系；在准确量化内部结构的基础上，发展基于多核CPU的离散元并行程序，对具有复杂边界的大型颗粒体系进行模拟。通过本项目的研究，将明确细观结构及其演化对剪切带的形成和发展所起的关键作用，确立宏观力学响应对细观组构参数的依赖关系，建立宏观颗粒动力学的细观理论，揭示颗粒材料渐进破坏的物理机制。

中文关键词： 颗粒材料；离散元；细观结构；剪切带；渐进破坏机理

英文摘要： Progressive failure has been a classical problem in the field of geotechnical engineering. It is associated with deformation localization or shear banding, phase transition and is also related to damaging in granular materials. In order to explore the physical mechanism of progressive failure, multiscale analysis based on micro-meso mechanical tests and DEM (Discrete Element Method) numerical simulations are carried out in this project. For the purpose of characterizing the microscale contact force, mesoscale deformation and macroscale mechanical response involved in the progressive failure, a multiscale frame characterized by 'particle pair in contact -void cell-granular assembly' is proposed, in which void cell is regarded as a medium scale. Parallel DEM program suitable for multi-core processor will be developed with the accurate quantification of the internal structure of granular materials. The following issues will be clarified in this project: the key influence of the mesostructure and its evolution on the formation and devlopment of shear band, the dependce of the macroscale mechanical resoponse on the mesocscale fabric. The mesoscale theory of the macroscale granular dynamics will be established and the the physical mechanism in progressive failure of granular materials will be explored.

英文关键词： granular materials；discrete element method；mesoscale structure；shear band；failure mechanism