ABDELHAKIM Djalab

SAOUDI SOUFIONE , MESSAOUDI AYMEN

Etude expérimentale de l’influence des paramètres opératoires sur la fatigue des matériaux en contact mécanique

Chikh Zaki , Chikh Mohamed

Étude des propriétés structurales, électroniques et optiques des nouveaux matériaux à base de ZnO

Salmi Saber

Étude de l’endommagement tribologique des contacts mécaniques

Berbache Karim , Saadi Abdelwahab, ..

Étude de l'effet du dopage sur les propriétés optiques et électroniques du matériau semi-conducteur à base de ZnO

Material fatigue has become a crucial consideration in contemporary industrial engineering due to its significant influence on the strength and reliability of mechanical components within industrial systems. Understanding fatigue mechanisms under various operational conditions is vital for creating durable and long-lasting designs. This experimental study examines the fatigue behavior of locally manufactured materials subjected to rotational bending. The primary goals are to establish the fatigue limit for a specific number of cycles and the endurance limit. To characterize the material's fatigue strength, a set of identical specimens underwent cycles with a defined shape. The impact of three operational variables—hardness (H), surface roughness (Ra), and applied stress (σ)— on the specimens' lifespan (number of cycles) was analyzed through experiments conducted using a Taguchi L18 mixed design. In conclusion, the results were statistically evaluated using Response Surface Methodology (RSM) and Analysis of Variance (ANOVA). The findings indicate that applied stress is the most influential factor affecting the fatigue life of the specimens, followed by hardness. Furthermore, the high value of the coefficient of determination obtained from both the Taguchi method and the RSM demonstrates a strong correlation between the predicted and experimental results.

Citation

ABDELHAKIM Djalab , Khatir KHETTAB , ,(2025-11-20), Experimental evaluation of the effect of operating parameters on fatigue of materials subjected to mechanical stress,THE 2nd NATIONAL CONFERENCE ON PHYSICS AND IT’S APPLICATIONS,BOUSAADA, Algeria

L'objectif de cette étude est d'examiner expérimentalement le comportement en fatigue cyclique de l'acier au carbone de nuance C45 (également connu sous le nom de XC48). Ce type de sollicitation en fatigue est couramment observé dans de nombreux dispositifs et composants mécaniques soumis à des flexions rotatives ou à des vibrations. Les travaux expérimentaux ont été centrés sur la réalisation d'essais de fatigue sur des éprouvettes cylindriques lisses. Ces éprouvettes ont été soumises à des tests pour évaluer l'influence de divers paramètres opérationnels sur la fatigue due à la flexion rotative de l'acier C45, notamment : la dureté (H), la rugosité arithmétique (Ra) et la charge appliquée (Q) sur la durée de vie de l'éprouvette (l'évolution du nombre de rotations (N)). Les résultats ont été analysés statistiquement par le biais d'une analyse de variance (ANOVA). Enfin, les conclusions de cette étude mettent en lumière les facteurs qui contribuent à la réduction de la durée de vie des mécanismes.

Citation

ABDELHAKIM Djalab , Khatir KHETTAB , ,(2025-10-29), Étude expérimentale de l'effet des conditions d'exploitation sur la fatigue des matériaux en contact.,1st National Seminar on Structural Mechanics and Materials (SNMSM'25) October 29-30, 2025,M’sila, Algeria

The effect of solid particles on the degradation of contact surfaces has been studied extensively in recent years. The presence of these unwanted particles between two bodies in relative motion can damage the surfaces and lead to total failure of the mechanisms. This study focuses on two main aspects: firstly, the effect of solid contamination in lubrication on surfaces in rolling contact (specifically between cylindrical rollers) and, secondly, the influence of operating parameters such as load and speed on the tribological behavior of mechanical components, particularly with regard to the evolution of dimensional losses (wear). The Taguchi L9 orthogonal array was used to study the influence of three operating variables (contact type (C), speed (V) and load (Q)) on the wear response (W). The experimental results were analyzed using Response Surface Modeling (RSM) and Analysis of Variance (ANOVA). The results showed that contact type (C) was the dominant factor affecting wear in the contaminated rolling contact, contributing 71.21observed wear. Furthermore, the RSM wear models developed showed a strong correlation between predicted and experimental data, with coefficients of determination greater than 80results obtained in this study support the rationale for reducing the life of mechanisms in a contaminated environment.

Citation

ABDELHAKIM Djalab , ,(2025-09-03), Mathematical Modeling of Wear in Rolling Contacts: A Statistical Approach,9th International Conference of Mathematical Sciences (ICMS 2025) 03-07 September 2025, Maltepe University, Istanbul, Turkey,Istanbul, Turkey

In this experimental study we aimed to answer questions about the influence of solid particles in the lubricant on mechanical contacts. Specifically, we focused on the changes in operating temperature and wear in a rolling EHD contact. The primary objective of this research is to clarify the factors that contribute to the reduced life of mechanisms operating in contaminated environments.

Citation

ABDELHAKIM Djalab , ,(2025-05-06), Influence of sand contamination on wear and operating temperature in a rolling contact.,The First National Conference on Renewable Energies and Advanced Electrical Engineering NC-REAEE’25 Mai 06-07th, 2025,M’sila, Algeria

This research-work the statistical investigation of heat transfer rate on MHD Jeffery–Hamel (J-H) ternary hybrid nanofluid flow. Moreover, the flow is under the influence of thermal radiation, MHD, variable thermal conductivity ( ), stretchable-shrinkable inclined walls and temperature jump effects. In this situation there nanoparticles are considered (i.e. and ). We derive nonlinear ODEs from the governing nonlinear PDEs utilizing the similarity transformations. The numerical solution has been constructed using the Explicit Runge Kutta Method (ERKM) and the statistical investigation using the Regression, ANOVA. Moreover, this paper illustrating the influence of key factors on skin friction and heat transfer rate.

Citation

ABDELHAKIM Djalab , ,(2025-05-06), Statistical Investigation on Heat Transfer of MHD Hybrid Nanofluid Jeffery–Hamel Flow,The First National Conference on Renewable Energies and Advanced Electrical Engineering NC-REAEE’25 Mai 06-07th, 2025,M’sila, Algeria

Material fatigue is now an essential aspect of modern industrial engineering as it has a significant impact on the strength and reliability of mechanical components in industrial systems. The study of fatigue mechanisms under different operating conditions is critical to achieving durable, long-lasting designs. This experimental study investigates the fatigue behaviour of locally fabricated materials subjected to rotational bending. The main objectives are to determine the fatigue limit for a given cycle and the endurance limit. In order to characterise the fatigue strength of the material, a group of identical specimens were subjected to cycles of a specific shape. To analyse the effect of three operational variables - hardness (H), surface roughness (Ra) and applied stress (σ) - on the life (number of cycles) of the specimens, experiments were carried out using a Taguchi L18 mixed design. In conclusion, the results were statistically analyzed using Response Surface Methodology (RSM) and Analysis of Variance. The findings show that the applied stress is the most significant factor affecting specimen fatigue (lifetime), contributing 38.53%, followed by hardness. Additionally, the high value of the coefficient of determination, derived from the Taguchi method and the developed RSM, clearly demonstrates a strong correlation between the predicted and experimental data.

Citation

ABDELHAKIM Djalab , , (2025-04-28), The Role of Material Properties and Operating Conditions in Fatigue Life Prediction: An Experimental and Statistical Approach, International Journal of Multiphysics, Vol:19, Issue:1, pages:967-979, scopus

Il est désormais bien établi qu'une particule solide en suspension dans un lubrifiant, lorsqu'elle traverse un contact mécanique, peut entraîner une dégradation rapide des composants des machines. Nous nous sommes particulièrement intéressés à la dégradation des contacts roulants, notamment ceux entre galets cylindriques. L'étude présentée s'est principalement concentrée sur l'évolution de la rugosité de surface Ra (état de surface) en fonction de divers paramètres de fonctionnement, tels que la charge, la vitesse, le temps, la concentration de contaminants, etc. Ce document expose les résultats d'une investigation expérimentale sur la dégradation des contacts EHD dans des conditions de contamination extrême, en présence de sable. L'analyse statistique des résultats permet d'établir une relation fonctionnelle entre le paramètre y (paramètres de sortie) et les facteurs xi (paramètres d'entrée). L'objectif principal de cette étude est d'expliquer les raisons de la réduction de la durée de vie des mécanismes dans un environnement contaminé.

Citation

ABDELHAKIM Djalab , ,(2024-11-17), L’effet de la présence des particules polluantes sur les surfaces en contact tribologique,The 8th National Colloquium on Inductics : University – Industry,M’sila, Algeria

The present study investigates the combined effects of Velocity Slip and Nanoparticles aggregation on Heat transfer analysis of MHD nanofluid (ie. 𝑻𝒊𝑶 − 𝑶 ) flow between porous convergent divergent channel. The modified Krieger–Dougarty and Maxwell–Bruggeman models were utilized to nanoparticle aggregation. The modeling based on nonlinear PDEs such as continuity, momentum and heat equations, these equations transformed to a system of nonlinear ODEs using similarity transformations then solved numerically and analytically, the analytical solution has been constructed using by ADM method, the present results in particular cases are compared to results obtained by the HAMpackage and by the Runge- Kutta Fehlberg 4th–5th order (RKF-45) for validation. The effects of active parameters on the velocity, temperature and concentration, skin friction and Nusselt numbers are investigated.

Citation

ABDELHAKIM Djalab , ,(2024-11-17), MHD Of 𝑻𝒊𝑶𝟐 − 𝑬𝑮 Flow Between Convergent-Divergent Channel With Velocity Slip And Nanoparticles Aggregation,The 8th National Colloquium on Inductics : University – Industry,M’sila, Algeria

This study investigates the 3 flow characteristics of a tetra hybrid nanofluid over a stretching sheet,while accounting for thermal radiation and shape factors (i.e Sphere, Column and Lamina) and Casson base liquid (i.e Blood) effects is presented in this work. In this situation both nanoparticles are considered (i.e. and ). We derive nonlinear ODEs from the governing nonlinear PDEs utilizing the similarity transformations. The model's performance is assessed through both numerical and analytical solutions, the analytical solution has been constructed using using the Adomian Decomposition Method (ADM) and numerical using the Explicit Runge Kutta Method (ERKM) illustrating the impact of key parameters on velocity, temperature profiles, skin friction and Nusselt numbers. The present results in particular cases are compared both numerical and analytical results.

Citation

ABDELHAKIM Djalab , ,(2024-10-13), 3D flow of Casson hybrid nanofluid under thermal radiation and shape factors,1er Séminaire National : Eau, Environnement et Energies renouvelables (SN3ER’24),M’sila, Algeria

L'effet des particules solides sur la dégradation des surfaces de contact a fait l'objet de nombreuses études ces dernières années. En effet, la présence de ces particules indésirables entre deux corps en mouvement relatif peut endommager les surfaces et conduire à la destruction complète des mécanismes. Dans le présent travail, nous nous intéressons à comprendre, d'une part, l'effet de la contamination solide de la lubrification sur les surfaces en contact roulant (contact entre galets cylindriques) et, d'autre part, l'influence des paramètres de fonctionnement tels que : charge, vitesse, type de contact, ... etc, sur le comportement tribologique des pièces mécaniques (évolution des pertes de côte (usure)). Dans la deuxième étape, une étude statistique de l'effet des paramètres de fonctionnement (charge, type de contact, vitesse) sur la dégradation mécanique du contact est réalisée à l'aide de la méthodologie de surface de réponse (MSR) et de l'analyse de variance (ANOVA). Enfin, les résultats obtenus par cette étude, justifie les raisons de réduction de la durée de vie des mécanismes dans un milieu pollué.

Citation

ABDELHAKIM Djalab , ,(2024-10-12), Étude Expérimentale des Effets des Contaminants solides sur les Propriétés Tribologiques des Matériaux,Séminaire Sur La Technologie Et L’industrie,Tlemcen, Algeria

It is well-established that the presence of solid particles between contacting surfaces can significantly degrade the lifetime of machine components. This study focuses on investigating the failure of dry rolling contacts under the influence of solid contaminants. To achieve this, the researchers conducted experiments using a custom experimental setup that closely represents the real operating conditions of gears or roller bearings. Specifically, the dry rolling contact tests were carried out using the contact between two steel disks. In order to examine the influence of three operating variables - particle size (S), rotational speed (V), and load (Q) - on the studied response, which was wear (W), the Taguchi L9 orthogonal array was utilized. The analysis of the obtained experimental results was performed using both response surface methodology (RSM) and analysis of variance (ANOVA) techniques. The results revealed that particle size (S) was the dominant factor affecting the wear of the contaminated dry rolling contact, contributing 59.93% to the observed wear. Furthermore, the developed RSM models for wear demonstrated a strong correlation between the predicted and experimental data, with determination coefficients exceeding 75 Keywords: dry rolling contact, solid particles, Taguchi technique, wear, Statistical Analysis

Citation

ABDELHAKIM Djalab , ,(2024-07-19), Statistical Analysis of Wear in Contaminated Dry Rolling Contacts,12th International Conference on Applied Analysis and Mathematical Modeling, 2024 (ICAAMM 2024), Istanbul, Turkey,Istanbul, Turkey

In the field of mechanical manufacturing, the casting process is considered the most important process in making complex parts. We use several alloys to obtain the final product that matches the properties we want. However, when this process is inaccurate, it may have some defects. Such as the holes observed on the metal structure, which result from nitrogen gas, which contributes to reducing the density of manufactured parts. In this research, we study the effect of changing the density value of lead metal on the value of the mechanical stresses applied to it. This change in density is the result of the increase in the number of holes resulting from the cooling process. Inside a scientific laboratory, we conduct our experiments on samples measuring 20 × 5 × 5 cm3. We cool molten lead in three ways: air, water and oil .The results show that the density of lead changes between 2.4% and 3.7%. The mechanical tension value on the samples changes between 12.6% and 17.3%. These results enable us to understand the relationship between density, type of cooling, and the tensile strength of the metal. Keywords : Casting . Metal. Density .Mechanical stresses.

Citation

ABDELHAKIM Djalab , Benfredj Amal, Fidjah Abdelkader, et al, ,(2023-11-25), The Effect Of The Type Of Cooling On Tensile Stresses İn Lead Metal,BİLSEL INTERNATIONAL HARPUT SCIENTIFIC RESEARCHES CONGRESS, 25-26 NOVEMBER, 2023,ELAZIĞ/TÜRKİYE

The effect of solid particles on the degradation of contact surfaces has been the subject of numerous studies in recent years. In fact, the presence of these unwanted particles between two bodies in relative motion can damage surfaces and lead to complete destruction of mechanisms. Indeed, we are particularly interested in the degradation of the rolling contact (contact between cylindrical rollers). The study presented was mainly devoted to the evolution of temperature, wear and surface roughness Ra (the surface condition) as a function of operating parameters such as load, speed, time and pollutant concentration, etc. For the contact: 100C6 steel bearing and C45 steel specimen. The processing of the results obtained also made it possible to deduce mathematical models of wear and roughness according to the parameters studied. Finally, the results obtained by this study justify the reasons for reducing the lifetime of the mechanisms in a polluted environment. Keywords: Contact - Solid Pollution - Wear - mathematical model - surface roughness

Citation

ABDELHAKIM Djalab , ,(2023-10-11), Study the effects of the presence of contaminant particles in mechanical contact,6th International Conference on Recent Trends in Multi-Disciplinary Research (ICRTMDR-23),Istanbul, Turkey

Dans cette étude expérimentale, nous avons tenté de répondre à des questions concernant l'influence des particules solides présentes dans les lubrifiants sur le contact mécanique. En effet, nous nous intéressons particulièrement à l'évolution de la température de fonctionnement et à l'usure des contacts roulants EHD. L'objectif principal de cette étude est d'élucider les causes de la durée de vie mécanique réduite dans des milieux pollués. Mots-clés: Contact - Pollution solide - Lubrification – Température - Usure.

Citation

ABDELHAKIM Djalab , ,(2023-07-11), Effet des contaminants du sable sur l'usure des contacts élastohydrodynamiques,4th International Conference of Mechanics and Materials ICMM’2023,Université farhat abbas 1 Setif

Cu2O is a semiconductor material largely used in electronics filed, especially in advanced solar cells. In order to improve its proprieties, theoretical calculations of the optical and electrical properties of Au-doped Cu2O was carried out in this work through the BIOVIA materials studio by the CASTEP code, which is based on the Functional Density Theory (DFT), the PDOS (Partial Density Of States) calculations of the copper and the oxygen atoms in the cuprite Cu2O material proved that the doping of the copper atom in the cuprite has a very large influence on its optoelectronic properties than the doping of oxygen one. The increase of the replacing percentage of the copper by the gold increases improvement of these properties (permittivity, conductivity, reflectivity and absorption).The (75 %) partial replacement of copper by gold (Cu0.25Au0.75O2) leads to a significant improvement in its band structure where we find it decreasing from 2.3 to becoming 1.2 eV. Keywords: Cu2O, solar energy, DFT, optoelectronic properties, semiconductors, doping.

Citation

ABDELHAKIM Djalab , ,(2023-03-12), Theoretical study and DFT calculations of optoelectronic proprieties of Audoped Cu2O,3 rd National Conference on Applied Physics & Chemistry (3rdNCAPC23),Normal School of Laghouat (ENSL)

The main objective of this present work is to theoretically study new semiconductor materials based on zinc oxide ZnO, namely the structures of the crystal lattice, the structure of electronic bands, and the general optical characteristics using the code castep (Biovia Material Studio) which is based on density functional theory DFT. The results obtained proved that the theoretical calculations of the optical and structural properties are very close to the experimental results (gap energy, optical conductivity, etc.), and also showed that the partial replacement of Zinc by titanium in the oxide of zinc leads to a significant improvement in its optoelectronics properties. Keywords: Zinc Oxide (ZnO), Ti, DFT, CASTEP, GGA, Optoelectronics properties.

Citation

ABDELHAKIM Djalab , ,(2022), Investigating the structural, electronic, and optical properties of novel ZnO-based materials,2nd International seminar on industrial engineering and applied mathematics,Université 20 Août 1955-Skikda

Un semi-conducteur est un corps cristallin dont les propriétés de conductivité électrique sont intermédiaires entre celles des isolants et des conducteurs, elles varient sur plusieurs ordres de grandeur, sous l'effet de la température, l'éclairement, la présence d'impuretés (dopage). L’oxyde de zinc (ZnO) est un semi-conducteur présent des propriétés électriques et optiques intéressantes. Ce présent travail a pour objectif principal d’étudier théoriquement de nouveaux matériaux semi –conducteurs à base de l’oxyde de zinc ZnO, à savoir les structures du réseau cristallin, la structure de bandes électroniques, et les caractéristiques optiques générales en utilisant le code castep (logiciel materials studio) qui est basé sur la théorie de la densité fonctionnelle DFT. Les résultats obtenus ont prouvé que les calculs théoriques des propriétés optiques et structurelles sont très proches des résultats expérimentaux (énergie de gap, conductivité optique....etc), et montré également que le remplacement partiel du Zinc par de l'argent dans l’oxyde de zinc conduit à une amélioration significative de ses propriétés optoélectronique où l'énergie de gap devient proche de 1 eV.

Citation

ABDELHAKIM Djalab , ,(2021), Étude de l'effet du dopage sur les propriétés optiques d'un matériau semi-conducteur,1ere Conférence Internationanle sur les procédés industriels et la conservation environnementale,Université 20 Août 1955-Skikda

Dans ces dernières années, l'effet des particules solides sur la dégradation des surfaces en contact a fait l'objet de nombreuses études. En effet, la présence de ces particules indésirables entre deux corps en mouvement relatif, peut endommager les surfaces et conduire à la destruction totale des mécanismes. Ce travail s’intéresse principalement aux effets de la pollution solide sur la dégradation des contacts purement secs, se traduisant par l’évolution de l’usure, et de la température de fonctionnement.

Citation

ABDELHAKIM Djalab , ,(2017), Dégradation des contacts mécaniques secs dans les milieux pollués,La 4ième Conférence Internationale sur la Maintenance et la Sécurité Industrielle,Université 20 Août 1955-Skikda

Nowadays, it is well established that the degradation caused by the presence of solid particles between the contacting surfaces can severely reduce the lifetime of machine components. This study focuses on the failure of a dry rolling contact under the effect of solid contaminants. To achieve this goal, experiments have been conducted on an original experimental set-up which represents the real operating conditions of gears or roller bearings. In fact, dry rolling contact tests are carried out using the contact between two steel disks. In order to investigate the influence of three operating variables which are: Particles size (S), Rotational speed (V) and Load (Q) on the studied responses (i.e. wear (W) and surface roughness (Ra)), the Taguchi L9 orthogonal array was adopted. The analysis of the obtained experimental results is achieved using both response surface methodology (RSM) and analysis of variance (ANOVA) techniques. The results display that the particles size (S) is the dominant factor affecting the wear of a contaminated dry rolling contact (S: 59,93%), whereas it is found that the applied load (Q) has the most significant effect on the surface roughness (Ra) (Q: 69,94%). Finally, from developed RSM models of wear and surface roughness, it is judged that the obtained higher values of determination coefficient (more than 75%) show clearly the high correlation between the predicted and experimental data.

Citation

ABDELHAKIM Djalab , , (2016), Mathematical Modeling and Statistical Analysis of Wear and Surface Roughness in Contaminated Dry Rolling Contacts, Journal of the Balkan Tribological Association, Vol:4, Issue:22, pages:4593-4617, Scientific Bulgarian Communications