基于CT切片的三维混凝土细观层次力学建模  

MESO-LEVEL MODEL OF THREE-DIMENSIONAL CONCRETE BASED ON THE CT SLICES

作　　者：秦武[1,2] 杜成斌[1] 

机构地区：[1]河海大学工程力学系,江苏南京210098 [2]中交第三航务工程勘察设计院有限公司,上海200032

出　　处：《工程力学》2012年第7期186-193,共8页Engineering Mechanics

基　　金：国家自然科学基金项目(50779011;11132003);973课题项目(2007CB714104)

摘　　要：基于CT切片研究混凝土数值模型的三维重构,可以为揭示混凝土破坏机理研究提供更好的研究对象。基于数字图像技术和MATLAB图像处理工具,针对混凝土截面CT切片研究混凝土三维模型的重构技术。应用CT技术获取混凝土试件截面切片,应用底帽变换等方法将CT切片处理为三值图片,考虑孔隙影响,并基于体数据法重构混凝土三维模型。基于网格映射方法,重点研究了单元属性控制因素,提出更精确的单元属性识别判断准则,得到了与试件真实骨料配比相近的三维有限元网格模型。对重构的混凝土试件的四点弯拉断裂过程的非线性有限元分析表明,数值分析的弯拉曲线与破坏形态都与实验结果有较好的相似性,数值模型能较好的模拟实际混凝土试件的破坏。The three-dimensional reconstruction concrete model based on CT slices can provide a better research model for revealing concrete failure mechanism. Having taken CT slices of a concrete section, the reconstruction technology for a three-dimensional （3D） concrete model is mainly studied in the paper by the digital image technology and MATLAB image treatment tool. The pore in the concrete is taken into consideration in the model, the CT slice of the concrete section is composed of three-value pixels by bottom cap treatment, and the 3D structure of concrete specimen is reconstructed, based on the method of volume data. The controlling factors of unit attributes are studied in detail, based on the method of mesh mapping. A more accurate judgment criterion of unit attribute recognition is proposed, and the 3D finite element mesh model with the same aggregate proportion as the specimen in the experiment is established, and the four-point bending-tension fracture process for the reconstructed beam is analyzed by the nonlinear FEM. Numerical results show that the bending curve and failure shape of the reconstructed model are quite identical with the those of the experiment.

关 键 词：混凝土 细观分析 CT切片 三维重构 非线性有限元 

分 类 号：TU528.01[建筑科学—建筑技术科学]