This paper presents the integration of muscle fatigue modeling into the finite element solver PAK, based on an extended version of Hill’s phenomenological model. While traditional muscle models focus primarily on force generation, this study incorporates fatigue dynamics to provide a more realistic representation of muscle performance over ti...

By Boban Stojanović, Miloš Kojić, Srboljub Mijailovich

This paper describes software developed based on numerical implementation of algorithms for coupled acoustic – structure interaction. This class of problems implies coupling of the fluid domain, with sound wave propagation, and the domain of solid, which vibrates under the pressure caused by sound waves from the fluid domain. The physical beh...

By Velibor Isailović, Nenad Filipović, Milica Nikolić, Miloš Kojić

Cardiovascular diseases are among the leading causes of mortality worldwide, necessitating advanced computational modeling to study their underlying mechanisms and explore potential treatments. In this paper, we present a multiphysics computational model that integrates cardiac mechanics, electrophysiology, and mass transport, implemented within th...

By Miljan Milošević, Bogdan Milićević, Vladimir Simić, Nenad Filipović, Miloš Kojić

X-ray angiography is one of the diagnostic procedures applied in clinical practice to analyze the state of patient-specific coronary arteries. During this examination a parameter called fractional flow reserve (FFR) is invasively measured to quantitatively assess the existence of potential stenosis and its significance. The software proposed in thi...

By Tijana Đukić, Ognjen Pavić, Lazar Dašić, Tijana Geroski, Nenad Filipović

In this paper, we give a short overview of the basic concept of stress integration for inelastic material models. This methodology was introduced by the author, initially for thermo-elasticplastic and creep deformation of metals, termed as ‘effective-stress-function’ (ESF), and then generalized to the ‘governing parameter method&r...

By Miloš Kojić

The paper presents various examples of the application of the PAK software and its modules for thermal, filtration, and stress–strain analysis of different complex engineering structures such as gravity dams, arch dams, embankment dams, tunnels, and mines. Examples of research, studies, and projects in which PAK has been applied to assess the...

By Dejan Divac, Slobodan Radovanović, Maja Pavić, Nikola Milivojević, Vladimir Milivojević, Miroslav Živković, Dragan Rakić, Snežana Vulović

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 explores the dynamics and stability of measles infection within a specified population, utilizing the SEIRV+D model. The study commences by establishing the equilibrium points and determining the reproduction number. The stability of this equilibria is contingent on the calculated reproduction number. The research draws upon real data ob...

By Maja Kukusheva Paneva, Natasha Stojkovik, Vladimir Milićević

The need for effective CPU cooling has become increasingly important with the growing demand for computing performance. In this paper, we numerically investigate the problem of active CPU cooling using hybrid nanofluids. The studied heatsink consists of a parallelepiped-shaped block filled with a hybrid nanofluid, crossed by four tubes through whic...

By Melouka Benyamina, Abderrahim Mokhefi

Lie derivative plays a key role in mathematics and physics. In particular, the Lie derivative discretization scheme has been implemented for a relatively large time step in order to quickly solve the numerical solution of the system. In this paper, an algorithm of the Lie derivative discretization scheme is applied to variable mass systems. Four di...

By Xinyue Jia, Chang Liu, Wenan Jiang