Application of a micro-model for concrete to the simulation of crack propagation

Abstract

The PeriDynamics (PD) model of material fracture can simulate the nucleation and propagation of cracks naturally with a simple bond breakage criterion. Combined with its advantages in multi-scale, the crack characteristics of concrete can be simulated from micro-scale. Therefore, the micro-calculation model of concrete was established by the spherical growth model based on the MATLAB-ABAQUS co-simulation method. Meanwhile, combined with the plastic softening characteristics of concrete, a quasi-plastic damage fracture constitutive model for concrete was established. Finally, the mode-I fracture test and two typical mixed-mode fracture tests were simulated by this model, and the PD-FEM (finite element method) method was used to reduce the calculation cost, in which the cracking regions were set as the PD model and other regions were set as the FEM model. The results show that the crack initiation and propagation of different calculation samples can be well described by the calculation model. Moreover, the proposed material model can better reflect the comprehensive mechanical behavior of concrete, and the crack path of the specimens is consistent with the test results. For the simulation of the I-II (tension shear) mixed fracture test, the crack paths of different calculation samples with small shear load are obviously different, and the range of crack paths can be predicted by the simulation of calculation samples. Furthermore, for the calculation samples with large shear load, the crack path and macro-behavior of different calculation samples are close to each other.