Date: 02/28/2019, 14:00
Candidate: Juan Esteban Alvarez
Advisor: Prof. Paulo Sollero
Abstract:
In this work, a multiscale 2D dynamic transition for heterogeneous materials is proposed using the boundary element method (BEM). Owing to the change of elastic properties of the modeled scale, the isotropic behavior is considered at the macroscale and the anisotropic behavior at the microscale. The connectivity
between scales is formulated based on internal points from the macroscale. As a result, the displacement field is known, which is used as a prescribed boundary condition at the microscale. The transient analysis is implemented by the dual reciprocity method (DRM) to evaluate the non-linear and time-dependent problem. In addition, the Houbolt algorithm is used as the time integration method. At the microscale, the polycrystalline aggregate is reproduced using Voronoi tessellation. This model contemplates the stochastic morphology and random crystalline orientations for each grain. Subsequently, the interfaces of grains are studied using the multiscale cohesive zone model (MCZM), and a consequence, the strain energy is transferred to disrupt a homogenized atomistic arrangement. In order to describe the energy between atoms, the embedded atom model (EAM) potential is used. Thereby, from the rupture of atomic bonds due to the interatomic forces, simulations of intergranular failures are obtained. Finally, verification tests are confronted with reference solutions in order to show the viability of this bridging methodology