Multiscale Computational Modeling of Brittle and Ductile Materials under Dynamic Loading

Multiscale Computational Modeling of Brittle and Ductile Materials under Dynamic Loading

Karamnejad, A. (TU Delft Applied Mechanics)

Sluys, Lambertus J. (promotor)

Delft University of Technology

2016-12-22

The computational homogenization method enables to derive the overall behavior of heterogeneous materials from their local-scale response. In this method, a representative volume element (RVE) is assigned to a macroscopic material point and the constitutive law for the macroscopic model at that point is obtained by solving a boundary value problem for the RVE. However, the standard computational homogenization scheme cannot be used when strain localization occurs and does not account for dynamic effects at the local-scale. Furthermore, in the computational homogenization scheme, at each iteration, a boundary value problem should be solved for RVEs associated to the integration points of macroscopic elements which leads to high computational cost. When the problem is nonlinear (material and/or geometrical nonlinearities), the computational cost may become more than used for direct numerical simulation (DNS).
This study aims at developing computational and numerical homogenization schemes which account for strain localization, dynamic effects at the local-scale and large deformations and strains. Furthermore, strategies are presented to decrease the computational cost while preserving accuracy. Different heterogeneous structures consisting of quasi-brittle materials, hyperelastic materials and polymer materials are studied and proper homogenization schemes are presented.

https://doi.org/10.4233/uuid:95a303ae-565c-41e9-91a7-0dea4d4207a1

978-94-6186-760-5

Institutional Repository

doctoral thesis

© 2016 A. Karamnejad