Discrete Element Modelling of Concrete Behaviour under Uniaxial Compressive Test

Abstract

This paper presents a three-dimensional (3D) simulation of the concrete behavior in a uniaxial compressive test using Discrete Element Modelling (DEM). The aim of this paper is to validate the numerical model developed and to study the cracking initiation and failure process in order to better understand the fracture behavior of concrete. The particles were distributed using an algorithm that is based on sieve test analysis. The parameters were set up in order to validate the numerical model with the experimental result. It was observed that the three-dimensional model with 44339 spheres is in line with the laboratory test in term of stress-strain response and macroscopic cracks development. Once the bond between the spheres was broken, it lead to the formation of microscopic cracks which were not visible in laboratory test. DEM can help to identify which part of a concrete structural element is more prone to the evolution of microscopic and macroscopic cracks. From the observation recorded during the testing, it is clear that DEM is capable of capturing concrete behavior both quantitatively and qualitatively. It is also possible to measure the strain energy stored in the linear contact bond and parallel bond. At the yielding point in the concrete the strain energy is released in the form of kinetic energy, frictional slip energy, energy of dashpot and local damping. This can be extended further to calculate fracture energy in the future works. Hence, it can be concluded DEM can be used to study the random nature of the cracking and fracturing of concrete structures.