Application Of Graphics And Image Processing In The Concrete Aggregate Modeling

Due to the long period and the huge cost of large numbers of human and financial resources, as well as its large randomness, the scope of concrete macro-experiment study is severely restricted. With the development of computer technology, more and more studies begin to focus on the meso-level research, which regards concrete as a multiphase heterogeneous composite material, constituted by coarse aggregate, mortar and the adhesion between aggregate and mortar, and then makes up for the defects and shortcomings of macro-analysis. From the perspective of concrete materials, according to software engineering, and based on data structures, computer graphics and image processing, this paper mainly focused on two generation methods based on two-dimensional and three-dimensional mesostructure of graphics and the finite element modeling of concrete block based on digital image technology. As a result, this study realized the automatic generation of concrete mesostructure.In the foundation of previous studies, the results are mainly as follows:First, the article proposes generation algorithms of different types of random aggregate models, which provide a practical and effective method of modeling for the concrete mesostructure. In interference judgments during the aggregate deliver process, the article introduces a new method—crossing method, which is simple, quick and easy to program, and furthermore, applicable to interference judgments of a various type of aggregate including ellipsoid, convex polyhedra in two-dimensional and three-dimensional.Second, the article proposes the intervention method based on the determination of volume on the basis of crossing method. And then by utilizing the intervention method, it generated two-dimensional and three-dimensional concrete specimen according to a certain graduation. The method could be extended to construction of concrete meso-model via the finite element software.Third, natural aggregate model is generated in polar coordinates. Delivered in accordance with the graduation using intersection method, the natural aggregate model of concrete is generated.Finally, image segmentation is conducted via digital image processing technology. The slices of concrete sections are breached up by introducing grayscale and Lab color space, respectively, and then they are merged. Mapping obtained digital images of concrete sections to finite element mesh, concrete numerical specimens with real internal characteristics are generated directly. Numerical examples demonstrate that concrete mesostructure by automatic generation is consistent with the real concrete in the statistical sense.