基于DIC技术的动载颗粒体系力链分布与破坏机理的研究

项目名称： 基于DIC技术的动载颗粒体系力链分布与破坏机理的研究

项目编号： No.11472145

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： 陈凡秀

作者单位： 青岛理工大学

项目金额： 86万元

中文摘要： 本项目采用理论分析、微细观光测实验及PFC2D数值模拟相结合的手段，利用统计方法研究动载作用下颗粒体系力链的发展与破坏机理。以力链屈曲-热力学连续介质本构模型为基础，考虑颗粒间力的传递特性，推导颗粒间接触力与颗粒位移之间的函数关系。对颗粒体系变形图像进行边缘检测，提取颗粒形心位置，利用DIC计算颗粒形心位移，获得颗粒间接触力。探讨法向和切向接触力之间的关系，设定强力链的力大小和角度的判据，建立动载作用下颗粒体系力链分配与传递的理论模型，形成动载下颗粒体系力链监测与追踪的实验方法。在观测环境和颗粒材料相同的条件下，开展动载作用下颗粒体系剪切和压缩实验研究及理论分析，利用统计方法探讨各种因素的影响规律，修正力链分配与传递模型。深入研究动载作用下颗粒体系力链破坏机理，利用实验测试与数值模拟相结合的手段，研究力链长度及持续时间，探讨颗粒体系力链破坏的参数表征，构建动载作用下力链破坏预测理论与方法。

中文关键词： 力链；机理；颗粒体系；数字图像相关；动态测量

英文摘要： This project uses the theoretical analysis, optical measurement, indoor geotechnical experiment and PFC2D simulation method, using the statistical method to study the development and failure mechanism of inter-particle force chain under dynamic load. Based on buckling deformation of force chain according to the thermodynamic theory, considering the characteristics of force transfer, the function between the contact force and particle displacement is derived. The deformation of granular material could be captured by CCD camera. the centroid position of each particle could be extracted. Displacement of the particle centroid could be obtained using digital image correlation (DIC), and then the particle contact forces could be acquired. Investigate the relationship between contact force of the normal and tangential and establish the theoretical model of force chain distribution and transmission, forming an experiment method force chain monitoring and tracking of particles system under dynamic load. In order to explore the effects of various factors, the shear and compression experiments under the same conditions are carried out. Make a comprehensive analysis of the experimental results and corrected the model of force chain distribution and transfer model. Using experiment measurement and numerical simulation method, the force chain length and duration are analyzed. Study the parameter characterization of force chain destruction and construct the force chain failure prediction theory and method under dynamic load.

英文关键词： force chain;mechanism;granular material;digital image correlation(DIC);dynamic measurement