IMPROVEMENT OF THE SPARSE MATRICES STORAGE ROUTINES FOR LARGE FEM CALCULATIONS
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
PARAMETRIC INVESTIGATION OF BAND GAP EFFECTS IN CHIRAL MICROSTRUCTURES
Vibration suppression has been thoroughly studied in the last few years. A number of methods has been proposed for this purpose. An evolving method lies in the search of band gap regions, that is, certain frequency ranges where vibrations are isolated. In the present investigation, a periodic unit cell of a chiral metamaterial has been created in o...
By Panagiotis Koutsianitis, Georgios K. Tairidis, Alexandros Kougkoulos, Georgios E. Stavroulakis
CORONARY ATHEROSCLEROSIS ASSESSMENT: A NEW ANATOMICAL, FUNCTIONAL, MORPHOLOGICAL AND BIO-MECHANICAL APPROACH
The aims of this work are to investigate and compare two different flow dynamics techniques (steady state - pulsatile flow) for endothelial shear stress calculation, compare lesion specific smartFFR and ESS values, as well as total vessel smartFFR and ESS values, and investigate the relationship between smartFFR and ESS to stress MBF (myocardial bl...
By Panagiotis K. Siogkas, Georgios-Eleftherios Kalykakis, Constantinos D. Anagnostopoulos, Themis P. Exarchos
PHYSICS-INFORMED NEURAL NETWORKS FOR ELASTIC PLATE PROBLEMS WITH BENDING AND WINKLER-TYPE CONTACT EFFECTS
Kirchhoff plate bending and Winkler-type contact problems with different boundary conditions are solved with the use of physics-informed neural networks (PINN). The PINN is built on the base of mechanics laws and deep learning. The idea of the technique includes fitting the governing partial differential equations at collocation points and then tra...
By Aliki D. Muradova, Georgios E. Stavroulakis
ON DIFFUSE INSTABILITY OF ORTHOTROPIC VISCOPLASTIC PLATES
Elastic strain is covered by the effective medium homogenization method inside a representative volume element (RVE). It has an incremental quasi rate-independent (QRI) form obtained by the endochronic concept of thermodynamic time. The rate dependence takes place by means of stress rate dependent value of the initial yield stress. Free meso rotati...
By Ljudmila T. Kudrjavčeva, Milan V. Mićunović
NUMERICAL ANALYSIS OF REINFORCED CONCRETE BEAM-COLUMN JOINT UNDER ACCIDENTAL IMPACT
The purpose of this study is to create a universal computational model of a plane-stressed joint element, which could be implemented as a special finite element of the beam-column subassembly integrated into the FEA procedure to improve its accuracy. The combination both of the finite element method and the finite difference method has been accepte...
By Sergey Savin
MANUFACTURING OF RAPID PROTOTYPES OF MECHANICAL PARTS USING REVERSE ENGINEERING AND 3D PRINTING
This article focuses on the design and manufacture of mechanical parts that have complicated shapes using the technique of reverse design using a scanner or an MMT for data acquisition in the form of a point cloud, using CAD software (CATIA). The digital model created is used for a virtual representation of the final product. Then we get the physic...
By Salah Amroune, Ahmed Belaadi, Moussa Menaseri, Noureddine Geroski, Barhm Mohamad, Khalissa Saada, Riyad Benyettou
COMBINED EFFECT OF THERMAL RADIATION AND VISCOUS DISSIPATION ON UNSTEADY FREE CONVECTIVE MAGNETO-HYDRODYNAMIC FLOW THROUGH AN IRREGULAR CHANNEL
This study is focused on the joint effects of thermal radiation and magnetic field on an unsteady flow of natural convective, electrically conducting fluid past an irregular vertical channel in the presence of viscous dissipation. The magnetic field is applied normal to the channel. The coupled ordinary differential equations (ODE) are obtained usi...
By T. L. Oyekunle, S. A. Agunbiade
A NUMERICAL ALGORITHM BASED ON THE RCW METHOD TO SOLVE A SET OF FIRST-ORDER ORDINARY DIFFERENTIAL EQUATIONS
This research paper deals with a numerical algorithm based on the RCW method to solve a set of first-order ordinary differential equations. In this algorithm, the answer of each equation is considered as a polynomial of degree 2. The coefficients used in this polynomial are categorized into groups of free and fixed coefficients. The free coefficien...
By M. Rahmanzadeh, T. Asadi, M. Atashafrooz
AN EXPERIMENTAL AND THEORETICAL STUDY OF THE REACTIVITY OF SELECTED CATECHOLAMINES AND THEIR PRECURSORS TOWARDS ASCORBYL RADICAL
Ascorbyl radical is often used as a biomarker of oxidative stress in human organism. It is a product of the antioxidant activity of ascorbic acid and it is not expected to react further with biologically important molecules. For the first time, the reactivity of catecholamines and their precursors was investigated theoretically and experimentally t...
By Dušan Dimić, Đura Nakarada, Miloš Mojović, Jasmina Dimitrić Marković