This paper presents a method for improving the numerical analysis of contact problems using a penalty formulation. Since contact phenomena are inherently nonlinear, particularly in the case of large deformations, an incremental solution strategy is required. Conventional Newton-Raphson algorithms often face convergence problems when many nodes make...

By Snežana Vulović, Miroslav Živković, Nenad Grujović, Marko Topalović

The interaction between the Finite Element Method (FEM) and Smoothed Particle Hydrodynamics (SPH) is crucial in multiphysics simulations of granular–structure systems, impacts, and material behavior. This paper presents a penalty-based contact algorithm with Coulomb friction for FEM–SPH coupling. The method accounts for static and dynam...

By Marko Topalović, Miloš Ivanović, Snežana Vulović, Aleksandar Nikolić, Miroslav Živković

Two-equation turbulent models are widely used in finite element analysis of fluid flow. The PAK program package was upgraded from the classical laminar flow to the turbulent k-omega model. The turbulence model was validated using the case of fluid flow in a backward-facing step channel. The analysis results show good agreement with experimental dat...

By Aleksandar Nikolić, Miroslav Živković, Nenad Filipović, Marko Topalović

This paper presents a comparative analysis of numerical simulations of blood flow through the left ventricle using SPH (LS-DYNA) and FVM (Ansys Fluent) solvers. Numerical simulations based on SPH and FVM methods can provide a more comprehensive understanding of cardiac blood flow patterns. In Fluent, left ventricle walls were modeled as boundary co...

By Marko Topalović, Aleksandar Bodić, Miloš, S. Pešić,, Miljan S. Milošević, Miroslav M. Živković

Efficient memory handling is one of the key issues that engineers and programmers face in developing software for numerical analysis such as the Finite Element Method. This method operates on huge matrices that have a large number of zero coefficients which waste memory, so it is necessary to save it and to work only with non-zero coefficients usin...

By Dragoljub Stevanović, Marko Topalović, Miroslav Živković

The purpose of this research was to investigate the prospect of continuous flow modelling in LS-DYNA using SPH-FEM coupling. The both methods (SPH and FEM) are based on the continuum mechanics, however, SPH implementation uses Lagrangian material framework, while FEM uses an Eulerian formulation for the fluid analysis, and Lagrangian formulation fo...

By Marko Topalović, Aleksandar Nikolić, Snežana Vulović, Vladimir P. Milovanović

In this paper, turbulent fluid flow is analyzed using a two-equation turbulent finite element model that can calculate values in the viscous sublayer. Implicit integration of the equations is used for determining the fluid velocity, fluid pressure, turbulence, kinetic energy, and dissipation of turbulent kinetic energy. These values are calculated ...

By Aleksandar Nikolić, Marko Topalović, Vladimir Simić, Milan Blagojević