Publications Internationales
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Item Mechanical alloying of the fe-cr mixture and stabilization of the sintered nanostructure by carbon addition(Bucureşti: Politehnica Press, 2021) Amirouche, Saïfi; Bezzazi, Boudjema; Nechiche, Mustapha; Azem, Saidhe present work concerns the mechanical alloying of the iron-chromium mixture (Fe20% Cr) and the evolution of the crystallite size before and after sintering at high temperature. A study was conducted on the stability of the nanostructure of the sintered material. The effect of adding carbon on the structure and the crystallite size was studied for the sintered material. The X-ray diffraction technique was used to identify the new phases and measure the crystallite size as well as the microstrains induced by mechanical alloying. Scanning electron microscopy revealed structural changes in the milled and sintered material.Item Effect of Alternating Hybridisation of Fibres on the Physico - Mechanical Behaviour of Composite Materials(Sciendo, 2023) Harb, Noura; Dilmi, Hamid; Bezzazi, Boudjema; Hamitouche, KahinaThe performance/weight ratio of fiber reinforced polymer matrix composites makes them the material of choice for structural applications in many fields such as aerospace, aeronautics, automotive and civil engineering...etc. In polymer matrix composites, the fibers used as reinforcement are mainly synthetic fibers such as carbon and/or glass fibers. To ensure the low cost of using fiber- reinforced materials in motor vehicles, it is proposed to selectively incorporate carbon fibers to enhance glass fiber composites along the roadway, and to enhance glass fiber composites along the main load path. For this purpose, we conducted a behavioral study of hybrid epoxy thermoset polymer matrix laminates to highlight the influence of alternate hybridization of glass and carbon fibers on the physical- mechanical behavior of the materials.The results obtained show that the alternated hybridation of the fibers has a significant influence on the tensile properties ; and it affected the density, hardness and flexural properties significantly.Item Effect of natural aging on the tensile properties and the toughness of friction stir welds of 2024-T3 aluminum alloy(Elsevier, 2023) Djili, Abderrahmane; Bezzazi, Boudjema; Zioui, Nadjet; Haboussi, MohamedDuring friction stir welding of metallic alloys, four different microstructure zones are formed in the weld, resulting in heterogeneous mechanical properties in this latter. In the case of aluminum alloys, these properties are bound to change with aging, whether natural or artificial. In this study, changes in the toughness and tensile behavior of friction stir welds in Al 2024-T3 alloy over time are investigated. Only specimens found to be defect free, by X-ray imaging, are tested. Characterized by the area under the stress-strain curve of the material, the toughness is found to be 19% lower after 24 months of natural aging. This decrease in toughness is mainly due to a loss of ductility as the elongation of the material drops by 27% while the ultimate tensile strength increases by 9%. The fracture zone and pattern remain the same for both natural aged and freshly welded specimens. These results can be used to estimate the service life of structures using such a material, as in aeronautics.Item The physicomechanical and thermal properties of Algerian Aleppo pine (Pinus halepensis) wood as a component of sandwich panels(SISEF - Italian Society of Silviculture and Forest Ecology, 2022) Lakreb, Nadia; Sen, Umut; Bezzazi, Boudjema; Pereira, HelenaAleppo pine (Pinus halepensis Mill.) is the main forest species of Algeria occu-pying more than 35% of the total forest area of the country. However, the physicomechanical and thermal characteristics of Algerian P. halepensis wood are not well-known. This research investigates the physical (moisture, density, swelling, and shrinkage), mechanical (bending strength and modulus of elastic-ity), and thermal (mass loss under combustion and pyrolysis as well as thermal conductivity) properties of P. halepensis wood from the Darguina (Bejaia) forest in Algeria. The results showed that Algerian P. halepensis wood with a mean density of 540 kg m-3 has good dimensional stability in swelling and shrinkage, with 116.43 MPa bending strength and a modulus of elasticity of 17,520 MPa. The wood shows a good thermal resistance under low-tempera-ture range and has a thermal conductivity of 0.21 W m-1 K-1. The overall results indicate that Algerian P. halepensis wood may be commercially exploited for construction and insulation applications, namely in the production of sandwich compositesItem Mechanical alloying of the fe-cr mixture and stabilization of the sintered nanostructure by carbon addition(Politechnica University of Bucharest, 2021) Amirouche, Saïfi; Bezzazi, Boudjema; Nechiche, Mustapha; Azem, SaidThe present work concerns the mechanical alloying of the iron-chromium mixture (Fe20% Cr) and the evolution of the crystallite size before and after sintering at high temperature. A study was conducted on the stability of the nanostructure of the sintered material. The effect of adding carbon on the structure and the crystallite size was studied for the sintered material. The X-ray diffraction technique was used to identify the new phases and measure the crystallite size as well as the microstrains induced by mechanical alloying. Scanning electron microscopy revealed structural changes in the milled and sintered materialItem Alkali treatment effect on physicochemical and tensile properties of date palm rachis fibers(Taylor & Francis, 2020) Bezazi, Abderrezak; Boumediri, Haithem; Garcia del Pino, Gilberto; Bezzazi, BoudjemaThis work aims to optimize the physicochemical and tensile properties of vascular fibers extracted from a local date palm rachis in Algeria. This fiber has a very specific composition and architecture and is different from the remaining fibers obtained from the six possible parts of the tree. For this purpose, a Taguchi orthogonal array design L16 was applied to reduce the number of experiments. The fibers were extracted from the rachis with two different methods (boiling and retting in water) and treated by NaOH with various concentrations (1%, 2%, 3%, and 5%) and for different durations (1, 4, 8, and 12 h). They were characterized using SEM-EDX, ATR-FTIR, XRD, and TGA to understand the effects of the extraction method and alkali treatment. A statistical treatment of the data was carried out based on the S/N ratio and ANOVA was performed to identify the most significant parameters affecting the tensile strength and the Young’s modulus of the fibers. A desirability function was developed to identify the optimal factors leading to the maximization of the tensile propertiesItem Flexural fatigue failure of concrete reinforced with smooth and mixing hooked-end steel fibers(Cogent, 2019) Saoudi, Nacira; Bezzazi, Boudjema�This paper presents an experimental study on flexural fatigue dynamic behavior of reinforced concrete. Steel fiber is used for the retrofitting and strengthening flexural members, by mixing short smooth steel fiber and hookedend fiber. By using Vibrophore HFP 150, dynamic loading was scanned at a resonance frequency of 100 Hz. Our objective is to examine the behavior of a specimen of 7 × 7 × 28 by a three-point bending test under high-level stress until it fails. Important research has been conducted to investigate the static and fatigue behavior of reinforcement. It was strengthened initially using one fiber, then using other additives. However, this research is not adequate to examine the flexural fatigue behavior of specimens by mixing different shaped fibers at different percentages. A further improvement in composite concrete performance is observed by mixing two steel fibers under high-level stress. The results are in alignment with the fatigue life data using Weibull distribution.Item Flexural fatigue failure of concrete reinforced with smooth and mixing hooked-end steel fibers(Cogent OA, 2019) Saoudi, Nacira; Bezzazi, BoudjemaThis paper presents an experimental study on flexural fatigue dynamic behavior of reinforced concrete. Steel fiber is used for the retrofitting and strengthening flexural members, by mixing short smooth steel fiber and hooked- end fiber. By using Vibrophore HFP 150, dynamic loading was scanned at a reso- nance frequency of 100 Hz. Our objective is to examine the behavior of a specimen of 7 × 7 × 28 by a three-point bending test under high-level stress until it fails. Important research has been conducted to investigate the static and fatigue behavior of reinforcement. It was strengthened initially using one fiber, then using other additives. However, this research is not adequate to examine the flexural fatigue behavior of specimens by mixing different shaped fibers at different per- centages. A further improvement in composite concrete performance is observed by mixing two steel fibers under high-level stress. The results are in alignment with the fatigue life data using Weibull distribution.Item Properties of multilayered sandwich panels with an agglomerated cork core for interior applications in buildings(Springer, 2017) Lakreb, Nadia; Knapic, Sofia; Machado, José Saporiti; Bezzazi, Boudjema; Pereira, HelenaItem Elaboration and characterization of composite material based on epoxy resin and clay fillers(Universidad Nacional Autónoma de México (UNAM), 2017) Laouchedi, Dalila; Bezzazi, Boudjema; Aribi, ChouaibThe present work aims at investigating the effect of locally produced clay (Algeria), along with the effect of their size and rate on physical and mechanical properties of the composite material. This study is divided into two parts: The first one is devoted to the study of the composite material based on epoxy resin with kaolin, using different size fractions at rates ranging from 2% to 20%. The second part examines epoxy resin-based composite with calcined kaolin (metakaolin) with regard to the influence of the structure, the particle size and the charge rate on the properties of the material. It is shown that the clay fillers give the epoxy resin different properties compared to the epoxy resin alone and, additionally, reduce the cost of materials. It was also observed that the fillers enhance the mechanical properties by increasing the rigidity of the material. There is a maximum value of 2.4 GPa to 18% kaolin, or more than 325% increase in the modulus of elasticity with respect to unfilled resin for the finer particle size. It was also found that the modulus of elasticity increases with increasing the loading rate. Indeed, the rigidity increases with increasing the filler rate. Moreover, for both fillers, lower fraction yields better results. Moreover, for both types of added fillers, lower fraction yields better results