Meso-modeling technology and application of concrete based on MPGM and FEM

To study the meso-mechanical characteristics of concrete containing aggregates, this paper proposes a novel concrete packing algorithm called the Material Point and Grid Mapping (MPGM) algorithm, which is derived from the material point method. This method adopts the core idea of MPGM, in which physical quantities (e.g., aggregate position information) are discretized into continuously distributed particles. The position information of these particles is mapped to grid nodes such that the node position information also reflects the aggregate position information. The geometric overlap between different aggregates is determined based on these nodes. Compared with traditional aggregate generation methods, this algorithm is applicable to aggregates of random polygonal shapes. In this study, the MPGM source program was used to generate a concrete model with two-graded aggregates; the aggregate morphologies include 2D random polygons constructed using the grid method. Subsequently, the generated 2D concrete numerical model files were imported into the commercial software Abaqus. The structural evolution of meso-concrete models under external forces was numerically analyzed using this finite element software. This work provides a reference for in-depth studies on the meso-structural changes of concrete.