Two-scale finite element model of multilayer blood chamber of POLVAD_EXT

The latest construction of heart prosthesis—Polish ventricular assist device (POLVAD_EXT) is made of polymer and biocompatible TiN nanocoating. The two-scale model of the POLVAD_EXT is based on the finite element method. The theory of nonlinear elasticity and elasto-plasticity is applied in computations. The model in microscale includes: model of residual stress in TiN nanocoating, working loading of the POLVAD_EXT and profile of surface of deposited TiN nanocoating. The analysis of the stress–strain state is performed in two scales for the blood chamber of the POLVAD_EXT. The verification of the calculated macroresults is prepared by applying Authors' FEM code and experimental digital image correlation data. The computed distributions of stresses and strains in macro- and microscales are helpful to determine the regions of blood chamber of the POLVAD_EXT considered as the failure-source areas.