https://www.ajol.info/index.php/srst/issue/feed Synthèse: Revue des Sciences et de la Technologie 2020-01-27T15:33:46+00:00 Pr Bachir REDJEL revue.synthese@univ-annaba.dz Open Journal Systems <p><em>Synthèse&nbsp;: Revue des Sciences et de la Technologie </em>is a half-yearly international peer-reviewed journal published by the Diroctorate of Publication of “Université Badji Mokhtar- Annaba” (Algeria) since 1996.</p> <p><em>Synthèse</em> is a multidisciplinary journal. Its scope covers the fields of pure and applied science, natural and life science, medicine, geology, architecture and engineering. It offers a space for publication of original experimental and theoretical research studies as well as review articles. Manuscripts should be submitted in English, French and Arabic.&nbsp;</p> <p>Other websites associated with this journal:&nbsp;<a title="http://dpubma.univ-annaba.dz/?p=82" href="http://dpubma.univ-annaba.dz/?p=82" target="_blank" rel="noopener">http://dpubma.univ-annaba.dz/?p=82</a></p> https://www.ajol.info/index.php/srst/article/view/192412 Molecular docking studies on arbutin analogues as inhibitors of tyrosinase enzyme 2020-01-27T15:33:31+00:00 Sabrina Benouis s.benouis@gmail.com Fouad Ferkous s.benouis@gmail.com Khairedine Kraim s.benouis@gmail.com Ahmed Allali s.benouis@gmail.com Youcef Saihi s.benouis@gmail.com <p>The arbutin presents the starting point of our work which aims to discover new inhibitors of the tyrosinase enzyme. Therefore, we have studied the activity of arbutin derivatives as inhibitors against mushroom tyrosinase based on the molecular docking.</p><p>Molecular docking studies were performed on a series of arbutin analogues retrieved from Zinc database (with 70% as similarity threshold).The arbutin analogues were docked within the active site region of mushroom tyrosinase (PDB: 2Y9X) using Molegro Virtual Docker V.5.0.</p><p>The results of molecular docking studies revealed that some analogues of arbutin have higher Moldock score (in terms of negative energy) than arbutin and the experimentally known inhibitors of tyrosinase, and showed favourable molecular interactions exhibiting common molecular interaction with Met280, His85, His61 and Asn260 residues of tyrosinase. Furthermore, the top docked compounds used in this work do not violate the Lipinsky rule of five.</p><p><strong>Keywords:</strong> Arbutin, Molecular docking, Tyrosinase, Inhibition</p> 2020-01-27T00:00:00+00:00 Copyright (c) https://www.ajol.info/index.php/srst/article/view/192419 Bouillies fermentées traditionnelles à base de céréales au Burkina Faso : diversité, technologies de production et microorganismes à potentiel probiotique associés 2020-01-27T15:33:33+00:00 Boureima Kagambèga alysavadogo@gmail.com Hama Cissé alysavadogo@gmail.com François Tapsoba alysavadogo@gmail.com Adama Sawadoga alysavadogo@gmail.com Cheikna Zongo alysavadogo@gmail.com Yves Traoré alysavadogo@gmail.com Aly Savadogo alysavadogo@gmail.com <p>Le but de ce travail est de fournir, à travers la recherche littéraire, les technologies de transformation des céréales locales en bouillies fermentées et les microorganismes à potentiel probiotique impliqués dans cette fermentation. Les bouillies sont vendues dans des conditions d’hygiène précaire, ce qui constitue un risque majeur de santé publique pour les consommateurs, surtout les enfants de moins de cinq ans. Le microbiote de ces bouillies est constitué de microorganismes probiotiques conférant aux consommateurs des effets bénéfiques. Parmi ces probiotiques rencontrés dans ces bouillies, on distingue les bactéries lactiques, les levures, les moisissures et certaines souches non pathogènes d’<em>E. coli</em>. Ainsi la diversité technologique a un impact sur la qualité des bouillies de façon générale et aussi sur le microbiote. La maîtrise des différents procédés technologiques et l’application des bonnes pratiques d’hygiène et de production permet un contrôle de la qualité microbiologique. Les voies d'optimisation des bouillies pour les rendre plus nutritives avec des qualités microbiologiques acceptables constituent un moyen efficace d’augmentation des macronutriments et de micronutriment.</p><p><strong>Mots-clés:</strong> Technologie, Céréales, Bouillies-fermentées, Alimentsprobiotique</p><p><strong>English Title:</strong> Traditional porridge fermented cereals in Burkina Faso: diversity, production technologies and microorganisms with associated probiotic potential</p><p><strong>English Abstract</strong></p><p>The aim of this work is to provide, through literary research, local cereal transformation technologies in fermented porridges and probiotic potential microorganisms involved in this fermentation. The porridges are sold under precarious hygiene conditions, which constitutes a major risk of public health, especially since the consumers are children under five years old. The microbiota of these porridges is made up of probiotic microorganisms giving consumers beneficial effects. Among these probiotics encountered in these porridges, lactic acid bacteria, yeasts, molds and certain non-pathogenic strains of <em>E. coli</em> are distinguished. Thus technological diversity has an impact on the quality of porridge in general and also on the microbiota. Pathways for optimizing porridge to make them more nutritious with acceptable microbiological qualities are an effective way to increase macronutrients and micronutrients.</p><p><strong>Keywords:</strong> Technology, Cereals, Fermented-porridges, Probiotic foods</p> 2020-01-27T00:00:00+00:00 Copyright (c) https://www.ajol.info/index.php/srst/article/view/192420 Flore des espaces verts urbains de la ville d’Atakpamé au Togo 2020-01-27T15:33:34+00:00 Folega Fousséni ffolegamez@live.fr Atakpama Wouyo ffolegamez@live.fr Kanda Madjouma ffolegamez@live.fr Konate Djibril ffolegamez@live.fr Gmadjom Kissao ffolegamez@live.fr Wala Kperkouma ffolegamez@live.fr Akpagana Koffi ffolegamez@live.fr <p>L’étude menée dans la ville d’Atakpamé au Togo a pour objectif de déterminer le niveau de diversité de ligneux des espaces verts urbains. La trame verte urbaine a été subdivisée en six compartiments à savoir les établissements, les concessions, les espaces peu exploités, les jardins/les parcs, les îlots forestiers/boisés et la voirie. Les inventaires forestiers ont été réalisés dans 134 placettes de surfaces comprises entre 400 à 3000 m<sup>2</sup>. Au total, 67 espèces d’arbres réparties en 54 genres et 28 familles ont été recensées. Les résultats montrent que cette flore est caractérisée par une forte prépondérance d’espèces exotiques confirmée par la proportion importante des espèces Pantropicales (11,94 %). Les densités en tige les plus importantes sont estimées dans les établissements (350 tiges/ha) et dans les concessions (180,80 tiges/ha), pour des surfaces terrière significative dans les établissements (39,30 m<sup>2</sup>/ha) et dans les forêts (12,52 m<sup>2</sup>/ha). Le stock moyen de carbone urbain est évalué à 39,12 tC/ha. Il ressort de cette étude qu’un aménagement contextualisé des espaces verts pourrait améliorer la résilience de la vie urbaine en atténuant les effets des ilots de chaleur à l’échelle locale.</p><p><strong>Mots-clés:</strong> Biodiversité, Foresterie urbaine, Diversité structurale, Gestion durable, Atakpamé</p><p><strong>English Title: </strong>Flora of urban green space of Atakpame city in Togo</p><p><strong>English Abstract</strong></p><p>The study carried out within Atakpame urban area in Togo aims to determine the level trees species diversity potential of urban green spaces. The urban green area has been subdivided into six compartments such as establishments, concessions, interstices, gardens/parks, forest/wooded islands and roads. Forest inventories were carried out within 134 sample plots with a minimum area ranging between 400 and 3000 m<sup>2</sup>. A total of 67 trees species belonging to 54 genera and 28 families were identified. The results show that flora is characterized by a strong preponderance of exotic species confirmed by the high proportion of Pantropical species (11.94%). The largest stem densities are estimated in establishments (350 stems/ha) and concessions (180.80 stems/ha). Significant basal area is observed in establishments (39.30 m<sup>2</sup>/ha) and forests (12.52 m<sup>2</sup>/ha). The average urban carbon stock is estimated at 39.12 tC/ha. It is clear from this study that a contextualization of parks, gardens and other green spaces management could strongly reduce the effects of global warming in urban landscape.</p><p><strong>Keywords:</strong> Diversity, Urban forestry, Structural diversity, Sustanable management, Atakpame</p> 2020-01-27T00:00:00+00:00 Copyright (c) https://www.ajol.info/index.php/srst/article/view/192422 Flux optimal de puissance comprenant un contrôleur UPFC par l'algorithme génétique et l'essaim de particules 2020-01-27T15:33:35+00:00 Ahmed Merah ahmed.merah@gmail.com Mohamed Adjabi ahmed.merah@gmail.com <p>Les recherches heuristiques inspirées de la nature basée sur l'algorithme génétique (GA) et l'essaim de particules (PSO) sont présentées et utilisées pour le problème de flux optimal de puissance (OPF), dans les systèmes d'alimentation avec un contrôleur de flux de puissance unifié (UPFC). Le coût total de production d'un système d'alimentation avec l'UPFC qui fixe la tension aux bus de charge est minimisé et validé de manière optimale avec l'utilisation de GA et PSO.GA, qui est basé sur la sélection naturelle et PSO, qui est basé sur le déplacement d'un groupe d'oiseaux sont des algorithmes d'optimisation proposés récemment. Les performances de GA et PSO ont été testées et vérifiées sur le système d'alimentation IEEE 30 bus en les comparants entre les deux et avec plusieurs autres méthodes d'optimisation. En outre, GA et PSO sont utilisés non seulement pour optimiser le coût total de production et les pertes de puissance active, mais aussi pour améliorer le profil de la tension du système d'alimentation. Nos résultats illustrent que GA et PSO peuvent être utilisés avec succès pour résoudre des problèmes non linéaires liés aux systèmes d'alimentation avec une préférence de la deuxième méthode.</p><p><strong>Mots-clés:</strong> Flux de puissance, optimisation, UPFC, algorithme génétique, essaims de particules</p><p><strong>English Title:</strong> Optimal power flow including a UPFC controller by genetic algorithm and particles swarm</p><p><strong>English Abstract</strong></p><p>Heuristics researches inspired by nature based on genetic algorithm (GA) and particle swarm optimization (PSO) are presented and used for optimal power flow problem (OPF) in power systems with a unified power flow controller (UPFC). The fuel cost of producing in power system with the UPFC that sets the voltage to the load buses is minimized and validated optimally with the use of GA and PSO.GA, which is based on natural selection and PSO, which is based on moving a group of birds are recently proposed optimization algorithms. The performance of GA and PSO have been tested and verified on the IEEE 30 bus power system by comparing between them and with several other optimization methods. In addition, GA and PSO are used not only to optimize the total cost of production and active power losses, but also to improve the voltage profile of the power system. Our results illustrate that GA and PSO can be used successfully to solve non-linear problems related to power systems with a preference of the second method.</p><p><strong>Keywords:</strong> Power flow, optimization, UPFC, genetic algorithm, particle swarms</p> 2020-01-27T00:00:00+00:00 Copyright (c) https://www.ajol.info/index.php/srst/article/view/192423 Architectures of a digital modulator for high-speed data transmission in telecommunication system 2020-01-27T15:33:36+00:00 Souhila Boudjema souhila_boudjema@yahoo.com Kaddour Saouchi souhila_boudjema@yahoo.com <p>Digital systems are more than necessary in our daily life. This last decade, the world is dealing with a remarkable technological revolution, especially, in the field of miniaturization of electronic devices such as modems and embedded systems. This work is focused on challenges of developing Quadrature amplitude modulation (QAM) digital modulators. In this context, this paper proposes several methods, simpler and efficient compared to the existing methods. The obtained results indicate that the proposed technique is effective in terms of data rotation calculation, particularly, for the sinusoidal signal generation in the QAM digital modulators. Through this study, an FPGA-based system with a maximum frequency of 550MHz is developed. The objective is to identify the optimal configuration facilitating data transmission in radio software. The obtained results were compared to recent works, and have showed a significant improvement in terms of computation time, especially in case of increasing the frequency of the transmission system at a very high rate.</p><p><strong>Keyword:</strong> Pipeline cordic, QAM, maximum frequency, throughput</p> 2020-01-27T00:00:00+00:00 Copyright (c) https://www.ajol.info/index.php/srst/article/view/192424 Etude hydrodynamique d’un nouveau bassin de décantation des eaux 2020-01-27T15:33:37+00:00 Nassima Lekouaghet nlekouaghet@gmail.com Yahia Hammar nlekouaghet@gmail.com Ouarda Djebabria nlekouaghet@gmail.com <p>Bien que le principe de la décantation soit connu depuis longtemps, il devient très complexe dans le cas de la sédimentation des particules plus ou moins floculées du fait du changement des propriétés physiques initiales des particules (forme, diamètre et densité).</p><p>Une modélisation de l’hydrodynamique d’un nouveau bassin de décantation est élaborée sur modèle réduit à échelle 1/20.</p><p>Les mesures des vitesses d’écoulement d’eau et l’étude de la distribution du temps de séjour du liquide au sein de l’ouvrage est réalisé au laboratoire, avec plusieurs particularités constructives afin d’améliorer ces performances hydrauliques avec injection d’air et sans air. Une comparaison est faite des résultats obtenus par simulation numérique en 2D et en 3D par Ansys Fluent.</p><p><strong>Mots-clés:</strong> Décantation, Modèle réduit, Similitude, Hydrodynamique, Modélisation, Simulation, Fluent</p><p><strong>English Title:</strong> Hydrodynamic study of a new water settling basin</p><p><strong>English Abstract</strong></p><p>Despite the principle of settling has been known for a very long time, it becomes very complex in the case of sedimentation of more or less flocculated particles due to the change in the initial physical properties of the particles (shape, diameter and density).</p><p>A hydrodynamic model of a new settling basin is developed on a scale model of 1/20.</p><p>Measurements of water flow velocities and the study of the distribution of the residence time of the liquid within the structure is carried out in the laboratory, with several constructive features in order to improve its hydraulic performance with air injection and without air. A comparison is made of the results obtained by numerical simulation in 2D and 3D.</p><p><strong>Keywords:</strong> Sedimentation, reduced model, Similarity, Hydrodynamics, Modeling, Simulation, Fluent</p> 2020-01-27T00:00:00+00:00 Copyright (c) https://www.ajol.info/index.php/srst/article/view/192425 Non-Linear robust control optimization to improving the aerodynamics in gas turbine 2020-01-27T15:33:39+00:00 Abdesselam Debbah a.debbah@univ-skikda.dz Hamid Kherfane a.debbah@univ-skikda.dz Mahieddine Berkani a.debbah@univ-skikda.dz <p>This paper presents a novel robust approach to control the aerodynamics instabilities, surge and rotating stall of a Variable Speed Axial Compressor (VSAC) in gas turbine process. The used model to design the controller is Egeland-Gravdahl who has been commonly recognized as standard when reporting some bifurcation behavior of VSAC which cannot be captured by constant-speed models. The proposed non-linear robust control is reformulated as an optimization problem, the first reformulation is linear matrix inequality (LMI) solved by interior point optimization algorithm, the second reformulation is non-linear constrained optimization solved by genetic algorithm (GA).The two optimization approaches are tested and compared using Matlab software. Promising simulation results were obtained for both optimization approaches, but the robust controller based on genetic algorithm optimization presents better performances to tackle a restricted specification and operating conditions.</p><p><strong>Keywords:</strong> Gas turbine, Surge-Rotating stall, Robust control, Constrained Genetic algorithm (GA)</p> 2020-01-27T00:00:00+00:00 Copyright (c) https://www.ajol.info/index.php/srst/article/view/192426 Free vibrations analysis of sandwich beams with viscoelastic core 2020-01-27T15:33:40+00:00 Yacine Karmi yyacine92@hotmail.fr Sabiha Tekili yyacine92@hotmail.fr Youcef Khadri yyacine92@hotmail.fr <p>In this work, we treat the problem of free vibrations of sandwich beams with viscoelastic core by considering its frequency dependence. The formulation of the equation of motion is carried out by the Hamilton principle whose Euler-Bernouilli theory is applied to the faces and the Timoshenko theory to the viscoelastic core. The discretization of the bending motion equation is carried out by the finite element methods to obtain the eigenvalues problem corresponding to linear free vibrations. The difficulty of solving the eigenvalues problem due to the frequency dependence of the stiffness matrix leads us to use the asymptotic numerical methodto get the<br />eigenmodes and the damping properties characterizing the viscoelastic sandwich beam.</p><p><strong>Keywords:</strong> Vibration, Finite element, Numerical asymptotic, Viscoelastic material, Complex eigenvalues, Damping properties</p> 2020-01-27T00:00:00+00:00 Copyright (c) https://www.ajol.info/index.php/srst/article/view/192427 Improvement of the characteristics of the bituminous concrete employed for the waterproofness of dams by the filler Bouhnifia dam (Algeria) 2020-01-27T15:33:41+00:00 Zoulikha Bounaadja bounaadja_z@yahoo.fr Lakhdar Djemili bounaadja_z@yahoo.fr Mouhamed Mansour Chiblak bounaadja_z@yahoo.fr <p>Bituminous concrete masks have historically been a real solution to the sealing organ of the dams and other hydraulic works, given the mechanical and hydraulic qualities of the material. The continuous progress in the design and construction of the masks of this type led us to carry out a study of its characteristics. A study in this direction to verify the resistance of the bituminous concrete mask from Bouhnifia dam to the solar effects shows that this mask can withstand these effects without the need for the thermal protection layer. In this work and to improve the characteristics of bituminous concrete, we studied the mechanical and physical characteristics of bitumen and stability on the slope. To do this, the percentage of filler in the mixture must be changed. Then samples must be prepared in the laboratory and tested. This study shows that the improvement of bituminous concrete with appropriate amounts of filler reduces the volume of vacuums; make the mixture denser and impermeable. However, excessive amounts of filler will significantly increase bitumen demand due to increased specific surface area, decrease creep, and increase percentages of imbibition and swelling.</p><p><strong>Keywords:</strong> Dam, Waterproofness, Bituminous concrete, Filler Stability</p> 2020-01-27T00:00:00+00:00 Copyright (c) https://www.ajol.info/index.php/srst/article/view/192428 Renforcement par soudure d’une section d’un élément de structure métallique 2020-01-27T15:33:42+00:00 Nadia Kouider nadia.kouider23@gmail.com Yazid Hadidane nadia.kouider23@gmail.com Fouzia Bouabdallah nadia.kouider23@gmail.com <p>Le procédé de soudage présente une modélisation très complexe car il implique des couplages entre des phénomènes mécaniques, thermiques et métallurgiques qui conduisent à la création des contraintes et des déformations résiduelles irrégulièrement distribuées au niveau de la section soudée. Cet article porte sur une étude expérimentale du comportement thermomécanique d’une poutre isostatique en profilé laminé renforcée par des éléments métalliques, assemblés au moyen de cordons de soudures et sollicitée par une charge concentrée (essai de flexion trois points). L’impact de la technique de soudure employée (cordons continus et discontinus) sur le comportement de l’élément est analysé. Des modèles numériques sont étudiés en utilisant un code de calcul basé sur la méthode des éléments finis où l’effet thermique dû à l’opération de soudage est pris en considération. Les résultats obtenus sont en très bon accord avec ceux expérimentaux.</p><p><strong>Mots clés:</strong> Soudage, Modélisation, Déformations résiduelles, Eléments finis</p><p><strong>English Title: </strong>A section reinforcement of a metal structure element by welding</p><p><strong>English Abstract</strong></p><p>The welding process presents a very complex modelling because it involves couplings between the mechanical, thermal and metallurgical phenomena which lead to the creation of stresses and residual strains irregularly distributed at the welded section level. This paper relates to a thermomechanical behavior's experimental study of an isostatic beam in reinforced rolled section of metallic elements by means of weld seams and solicited by a concentrated load (three-point bending test). The welding technique impact used (continuous and discontinuous weld seams) on the element behaviour is analysed. Numerical models are studied using a calculation code based on the finite element method, and the thermal effect due to the welding operation is taken into consideration. The obtained results are compared with those obtained experimentally. The results obtained are in very good agreement with the experimental ones.</p><p><strong>Keywords:</strong> Welding, Modeling, Residual deformations, Finite elements</p> 2020-01-27T00:00:00+00:00 Copyright (c) https://www.ajol.info/index.php/srst/article/view/192429 Corrosion evaluation of glass fiber reinforced plastic (gfrp) Tanks & pressure vessels using acoustic emission technology 2020-01-27T15:33:43+00:00 Mathias André salim.benmedakhene@utc.fr Denis Siguret salim.benmedakhene@utc.fr Anthony Foulon salim.benmedakhene@utc.fr Salim Benmedakhene salim.benmedakhene@utc.fr Pierre Mékarbané salim.benmedakhene@utc.fr Abdelouahed Laksimi salim.benmedakhene@utc.fr Christian Lemaitre salim.benmedakhene@utc.fr Jérôme Favergeon salim.benmedakhene@utc.fr <p>Corrosive environments are used like concentrated hydrochloric acid which is known to react with E-glass fibers. Acoustic emission results reveal different corrosion modes of glass fibers in HCl solutions. For the field applications, full scale GFRP equipment was instrumented with a range of AE sensors. The equipment is used for storage or process of corrosive chemicals. When this corrosive content comes in contact with the GFRP wall, via some failure of the corrosion barrier, this could lead to chemical degradation of the composite. To detect such phenomenon, two approaches were adopted: passive monitoring to detect active corrosion (equipment filled in with the service fluid) and AE monitoring during a proof test (according to ASTM E1067 standard). To correlate these AE measurements, the tanks were visually inspected and dissected. The AE results on field were also correlated with AE results in laboratory. The results of this work clearly show the efficiency of AE technology for glass fiber active corrosion detection. On the other hand, they show a good correlation between the proof tests and AE results of corrosion monitoring. The results of this research are a good basis for standardization of the corrosion monitoring of GFRP by Acoustic Emission.</p><p><strong>Keywords:</strong> corrosive environment ; hydrochloric acid; E-glass fibers ; acoustic emission</p> 2020-01-27T00:00:00+00:00 Copyright (c) https://www.ajol.info/index.php/srst/article/view/192434 Analysis and identification of short circuit faults in the complex's electrical distribution system SIDER El-Hadjar 2020-01-27T15:33:44+00:00 Hakim Benhamida benhamida.hakim@yahoo.fr Tarek Mesbah benhamida.hakim@yahoo.fr <p>The difficulty in calculating the short-circuit currents lies essentially in the determination of the value of the impedance of the fault, the traditional calculation method consists in locating the fault of maximum short-circuit current at the starting head in the networks distribution. The objective is to determine the maximum currents by each departure, then to verify the dimensioning and the thermal resistance of the various equipment‟s of the network and the future needs at the bar games 225kv, 63kv and 15kv. A new calculation of the short-circuit current must be calculated following the change of the topology of the distribution network to verify the reliability of the existing protection system. The calculation of short-circuit currents is a key step in qualifying the equipment to withstand the thermal and electromagnetic effects. The numerical method for calculating shortcircuits currents requires modeling and simulations of the network studied with Cyme, a reference software for electrical distribution networks.</p><p><strong>Keywords:</strong> initial short-circuit currents, power supply system (SIDER-El Hadjar), thermal equivalent short-circuit current, Cyme software</p> 2020-01-27T00:00:00+00:00 Copyright (c) https://www.ajol.info/index.php/srst/article/view/192435 Prévision de la durée de vie en fatigue de contact des roulements à billes d’une boite de vitesse 2020-01-27T15:33:45+00:00 Azzedine Amara amaraazedine2010@gmail.com Rabia Khelif amaraazedine2010@gmail.com Rabah Bourenane amaraazedine2010@gmail.com <p>Ce travail s'adresse à l'analyse par la méthode des éléments finis (MEF) du mécanisme de dégradation par fatigue de contact des roulements à billes. Ceci se manifeste sous forme de phénomène d’écaillage dû aux fortes charges appliquées.</p><p>Une méthode numérique par éléments finis a été utilisée pour calculer la durée de vie en fatigue des roulements à billes. Ces calculs prévisionnels nécessitent la connaissance des paramètres d’endommagement occasionnés par les sollicitations mécaniques et environnementales. L'étude montre une cohérence acceptable inférieure à 7% entre les résultats donnés par la MEF et la formulation analytique développée par Basquin. L'influence de la température, du coefficient de frottement, de la vitesse de rotation et de la charge appliquée sur la durée de vie des roulements à billes est traitée en utilisant l’équation de Basquin qui permet la prévision de la durée de vie des roulements à billes. L’indice de fiabilité est calculé et les paramètres d’influence sont étudiés.</p><p><strong>Mots-clés:</strong> Roulement à bille, fatigue, modélisation, MEF, durée de vie</p><p><strong>English Title:</strong> Prediction of the contact fatigue life of ball bearing in a gearbox</p><p><strong>English Abstract</strong></p><p>This work is addressed to finite element method analysis (FEM) of the mechanism contact fatigue degradation of ball bearings. This is manifested under form of peeling phenomenon due to the heavy loads applied.</p><p>A numerical finite element method was used to calculate the fatigue life of ball bearings. These predictive calculations require knowledge of the damage parameters caused by the mechanical and environmental stresses. The study shows an acceptable consistency of less than 7% between the results given by the FEM and the analytical formulation developed by Basquin. The influence of temperature, coefficient of friction, rotational speed and applied load on the service life of the ball bearings is treated using the Basquin equation which allows the prediction of the service life of the ball bearings. The reliability index is calculated and the influence parameters are studied.</p><p><strong>Keywords:</strong> Ball bearing, fatigue, modeling, MEF, lifetime</p><p><strong><br /></strong></p> 2020-01-27T00:00:00+00:00 Copyright (c)