Aplicação de modelos híbridos ldem-fem no estudo da resistência à tração do concreto

Abstract

When accurate answers about the behavior of concrete subjected to the processes of damage and fracture by tensile are wanted, experimental tests are the most viable option to achieve this objective. However, with the technological advance and the growing number of studies involving the application of numerical methods in solving engineering problems, the possibility of using complementary techniques capable of contributing to a better understanding of the results obtained through experimental analysis arises. Due to this, the present work seeks to validate the application of the Lattice Discrete Element Method (LDEM) in the study of the mechanical behavior of concrete subjected to direct and indirect tensile, through the joint use of this method with the Finite Element Method (FEM) in the simulation of direct tensile, splitting and flexural tensile tests. The parameters used to represent the properties of the simulated material were collected from studies by Silva (2019). From this, the random distribution of material properties in the solid was implemented to analyze the variability of toughness in numerically modeled samples. For the three simulated tests, two types of approaches were used, one based on a three-dimensional configuration and the other using a two-dimensional model. For the direct tensile test, the final dimensions of the sample represented by the 3D and 2D models were, respectively, 25 mm x 100 mm x 400 mm and 5 mm x 100 mm x 400 mm. For the splitting test, the two models had the same diameter of 100 mm, but different lengths, being 200 mm for the three-dimensional model and 5 mm for the 2D configuration. As for the flexural tensile test, the 3D model had dimensions of 100 mm x 100 mm x 400 mm, while the 2D model had the same dimensions as the two-dimensional configuration of the direct tensile test. The results obtained with the adopted methodology were quite satisfactory, considering that, in the three simulated tests, at least one of the models used was able to obtain representative values of tensile strength, in addition to correctly capturing the deformations and failure mechanisms, which contributes positively to the validation of the application of LDEM in the study of the behavior of concrete subjected to tensile. Keywords: Lattice Discrete Element Method; Finite Element Method; Abaqus/Explicit; numerical simulations; concrete tensile strength.