Abstract
The ventricle sometimes cannot work efficiently and therefore, must be outfitted with prosthesis-pulsatile ventricular assist device (VAD) often made of polyurethane (PU) and biocompatible TiN deposited by pulsed laser deposition (PLD) method. The values of compressive residual stresses are the biggest of all measured, when TiN nanocoating is deposited by applying the PLD method. The purpose of the present paper is development of the computer finite element method (FEM) code for the multiscale simulation of the stress – strain state for the PU/TiN blood chamber of VAD, which will be used to determine the most dangerous places at surface of the chamber under predicted loadings. The algorithms of finite elements mesh processing, implementation of boundary conditions and obtaining numerical solution are presented in this paper. The developed FEM code is based on the new approach to the simulation of multilayer materials obtained by using PLD method. The model in microscale includes two components – model of the initial stresses caused by deposition process and simulation of active loadings observed in the blood chamber of VAD. Predicted distributions of stresses and strains are helpful to define precisely the regions of blood chamber, which can be defined as the failure-source areas.