@ARTICLE{Nitka_M._Dwuskalowe_2011, author={Nitka, M. and Tejchman, J.}, number={No 3}, journal={Archives of Civil Engineering}, pages={313-330}, howpublished={online}, year={2011}, publisher={WARSAW UNIVERSITY OF TECHNOLOGY FACULTY OF CIVIL ENGINEERING and COMMITTEE FOR CIVIL ENGINEERING POLISH ACADEMY OF SCIENCES}, abstract={A two-scale numerical homogenization approach was used for granular materials. At small-scale level, granular micro-structure was simulated using the discrete element method. At macroscopic level, the finite element method was applied. An up-scaling technique took into account a discrete model at each Gauss integration point of the FEM mesh to derive numerically an overall constitutive response of the material. In this process, a tangent operator was generated with the stress increment corresponding to the given strain increment at the Gauss point. In order to detect a loss of the solution uniqueness, a determinant of the acoustic tensor associated with the tangent operator was calculated. Some elementary geotechnical tests were numerically calculated using a combined DEM-FEM technique.}, type={Artykuły / Articles}, title={Dwuskalowe numeryczne podejście do systemów granulowanych}, title={A two-scale numerical approach to granular systems}, URL={http://journals.pan.pl/Content/83779/mainfile.pdf}, keywords={Discrete element method, finite element method, granular material, homogenization technique, two-scale approach}, }