基于CT技术的混凝土三维有限元模型构建

Finite element 3D modeling of concrete based on computerized tomography

提出了一种基于CT数字图像技术的混凝土材料三维有限元模型构建的新方法。首先,采用医用CT扫描系统,对混凝土试样进行逐层扫描,生成材料的内部细观结构图像,利用CT图像的三维重构技术,将得到的剖面细观图像逐层叠加,形成三维细观结构图像;然后,将该图像映射到有限元程序中进行三维网格剖分,建立真实状态下的混凝土细观数值分析模型;在此基础上,对钢纤维混凝土进行了劈裂试验。结果表明,这种基于CT技术的数字图像三维有限元模型构建方法可真实地反应混凝土材料的内部结构与材料的固有力学特性,其数值分析结果与物理试验结果吻合,是数值分析领域中的一种新的尝试与创新。

A finite element 3D modeling method for mechanical analysis of concrete material based on digital CT processing, is put forward, Firstly the medical CT scanning system is set up to form the digital representation of material heterogeneity,the scanning process is repeated until the entire specimen can be represented by a series of layers the cuboidal elements.Secondly the digital image techniques are used to form the actual 3D mesostructures.The heterogeneity described by this mesostructures is approaching to the actual heterogeneity of concrete, which is mapped into the grid of finite element method, and a numerical model that can actually reflect concrete＇s heterogeneity is established.Numerical indirect tensile test of steel fiber concrete is processed by this method.The results show that this mathod based on CT can be used to calculate the mechanical responses of inhomogeneous concrete material with high accuracy,numerical analysis accord with physical test,and provides a new innoative method in the numerical analysis field.