Publications Internationales

Permanent URI for this collectionhttps://dspace.univ-boumerdes.dz/handle/123456789/13

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Author: search.filters.author.Daoui, AbdelhakimHas files: Yes

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    Failure Prediction of Laminated Composites: Simulation of the Nonlinear Behavior and Progressive Damage
    (Korean Fiber Society, 2023) Bensalem, Abdelhafid; Daoui, Abdelhakim; Cheriet, Abderrahmane; Lecheb, Samir; Chellil, Ahmed; Kebir, Hocine; Aissani, Linda
    The Hashin’s criteria are useful in composite structural applications because of their simple concept and their theoretical results are relatively close to that got in the experimental parts. In the present study, in the present study, the failure of the composite laminates under static loading have been developed predicted using Hashin’s Criterion. Nonhomogeneous stresses within a structure may induce a complicated failure scenario whereby one ply at a point can initiate failure and can affect also other plies at the same point or the same ply in different neighboring points. With neglecting the possibility of interlaminar failure, only in-plane loads are considered in this state. The results showed that the failure analysis was proposed to simulate the nonlinear laminate behavior and progressive damage of selected laminates under to their ultimate strength. In our approach, the finite element analysis is performed using MATLAB software to study the effect of tensile and compressive loading on the failure of epoxy resin laminate AS4/3501-6.
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    Identification of elasticity modulus by vibratory analysis (Application to a natural composite : aleppo pine wood) = Identification des modules d’élasticité par analyse vibratoire (Application à un composite naturel : bois de Pin d’Alep)
    (EDP Sciences, 2018) Daoui, Abdelhakim; Zerizer, Abdellatif
    In this paper, we present a method for the determination of the elasticity modulus in the vibratory domain of materials. This approach is based on research and interpretation of the spectrum of natural frequencies resulting from natural vibrations based on the theory of elastic beams. The tests consist of classical tests of longitudinal vibrations of natural composite beams (Aleppo pine wood), long enough to observe some natural frequencies. This identification method showed a good correlation between the theoretical and experimental values, notably the evaluation of the modal parameter for the case of the resonant frequencies and the identification of the modulus of elasticity of the materials used
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    Determination of elasticity modulus of aleppo pine wood (pinus halepensis mill) with the ultrasound method
    (2008) Daoui, Abdelhakim; Zerizer, Abdellatif; Marchal, Remy
    With a view to determining the mechanical properties - specifically the modulus of elasticity - of fibrous composites, the nondestructive methods present certain advantages. The ultrasound technique, based on measuring the propagation velocity of an impulse and considering the elasticity coefficients of the material, enabled us to deal with the study of a well-known local species, namely Aleppo pine (Pinus halepensis Mill.), with consideration of its physical parameters such as moisture and density. The mean goal of this step is to find correlations between the acoustic behavior of the material and its physical and mechanical characteristics
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    Use of wood waste (Aleppo pine) as a superplasticiser in self-compacting mortars
    (2014) Daoui, Abdelhakim; Safi, Brahim; Rezak, M.; Zerizer, A.
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    The use of seashells as a fine aggregate (by sand substitution) in self-compacting mortar (SCM)
    (Science Direct, 2015) Safi, Brahim; Saidi, Mohammed; Daoui, Abdelhakim; Bellal, Ahmed; Mechekak, Ali; Toumi, Kamel
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    Valorisation du bois de pin d'Alep par déroulage : optimisation de son étuvage = Optimisation of steaming prior to rotary peeling of Aleppo pine
    (2004) Daoui, Abdelhakim; Douzet, J.; Marchal, R.; Zerrizer, A.
    L'Algérie connaît un dynamisme démographique qui conduit à un plan de construction de logements très ambitieux. Le bois de construction est majoritairement importé d'Europe, alors que, parmi les ressources locales, les huit cent mille hectares de pin d'Alep algérien peuvent offrir une substitution partielle des matériaux bois importés. Des produits d'ingénierie bois d'intérêt pour la filière construction algérienne, le contreplaqué et le Lvl seraient potentiellement en bonne place. Ces deux produits sont issus du déroulage et, dans le cadre d'un projet Tassili qui vise la caractérisation et la valorisation du bois de pin d'Alep algérien, des essais exploratoires ont été menés pour déterminer les paramètres de déroulage ad hoc pour cette essence. Ce premier article traite de la préparation hygrothermique préalable du bois avant déroulage en prenant en compte quatre familles d'indicateurs pour déterminer une température d'étuvage qui soit un bon compromis. Ces indicateurs concernent : la propagation des fentes de recouvrance à coeur ; le désenrésinement du bois lors de l'étuvage ; la répartition d'eau dans le bois, facteur déterminant pour une prédiction de la durée d'étuvage ; l'évolution des efforts de déroulage en fonction de la température du bois. Une température de traitement de 50 °C apparaît être un bon compromis, à l'instar de celui utilisé dans le cas du pin maritime
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    Resistance to crack propagation of Algerian wood
    (2011) Kennouche, S.; Zerizer, A.; Aknouche, A.; Daoui, Abdelhakim
    Wood is the most building materials widely used since prehistory for the construction of houses, tools, weapons. Accidents occurring during the use of materials caused by different defaults, as: knots, resin pockets, cracks. These various defaults and others are the starting point of the principle of crack mechanics. Our present work focuses on determining the resistance to crack propagation of three types of Algerians wood, (Aleppo pine, eucalyptus and oak), by calculating the energy release rate G (mode I). The estimation of factor G allows the possibility of fracture propagation
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    Influence of veneer quality on beech lvl mechanical properties
    (2011) Daoui, Abdelhakim; Clément, D.; Rémy, M.; Zerizer, A.
    The quality of peeled veneers is generally quoted considering 3 main criteria: surface roughness, thickness variations and lathe checking. This last criterion impacts on mechanical properties of byproducts. It is well known that lathe checking occurrence can be reduced applying a good hygrothermal treatment of the round-wood before peeling coupled with optimised setting of pressure bar on the peeling lathe. It is also well known that thicker the veneer is and more difficult it is to reduce lathe checking and the other veneer defects. The tendency being to manufacture more eco-friendly engineering wood products using less glue, it is of interest to design such products with thicker layers and so less glue lines. But using ticker veneers should lead to a deterioration of final products mechanical properties. To quantify this effect, we have made 20-21mm thick LVL (Laminated Veneer Lumber) boards of beech (Fagus sylvatica) with various compositions (veneers 1, 3 or 5 mm thick). In order to obtained veneers enclosing different grades, several bolts of a same tree have been peeled following 4 different modalities changing wood conditioning temperature (20 / 70°C) and pressure bar settings (bar acting or not). The quality of all the veneers has been quantified before gluing. In total, 12 sets of boards have been produced for non destructive and destructive mechanical tests. The main results of these exploratory experiments are: - a quite low weakening of LVL mechanical properties when increasing veneer thickness. - the non destructive prediction of MOE by vibration seems not so good on LVL with thick veneers, especially in the case of edgewise loading, probably because of the presence of important lathe checks. - in some configuration, and especially when using thick veneers, it could be benefit to load LVL flatwise rather than edgewise. - for the measurement of shear strength on LVL, the 5-point bending test increases its efficiency when increasing veneer thickness. To properly order in a hierarchy the different veneer criteria impacting on LVL mechanical properties, new tests should be repeated on different LVL boards homogeneous for given criteria of veneer quality