Publications Internationales

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Author: search.filters.author.Nour, AbdelkaderHas files: No

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    Dynamic Behavior of Functionally Graded Turbine Blade Using Numerical Modeling
    (Springer, 2025) Houari, Amin; Guemmour, Mohamed; Amroune, Salah; Chellil, Ahmed; Nour, Abdelkader; Kouider, Bendine; Madani, Kouider; Campilho R.D.S.G.
    Turbine blade performance degrades under dynamic stresses from high temperatures and vibrations. design is challenging due to material limitations. Designers must minimize stresses, especially centrifugal forces, within acceptable material limits. the complex nature of these blades requires a seamless integration of design, material selection, and manufacturing processes to achieve the highest performance. thus, graded material properties are essential to control their behavior and ensure the longevity of the turbine blades during operation. this project aims to develop novel metal/ceramic functionally graded material (fgm) blade designs to enhance the lifespan of gas turbine rotors. A numerical study using the mesh method (umm) with the abaqus code will produce a 3d graded multifunctional material with controlled strength under different loading conditions. Our numerical analyzes of the behavior of a blade was carried out in two parts. The first studies the static behavior, using the tto homogenization method to define the elastoplastic zone of the fgm and a damage criterion for the fgm up to failure via the xfem technique. The second part analyzes the vibration behavior of the blade, considering various parameters such as the direction of the distribution of the fgm’s material properties according to thickness, and the effect of combinations of metals and ceramics, characterized by the exponent n of the power law. Numerical analyses using abaqus code for the metal model were validated experimentally. Analyzes of the fgm design has confirmed its validity in relation to the metal model. The results emphasize the importance of the distribution of material properties in fgm blades that significantly affect the stress distribution and modal analysis.
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    Mechanical properties and low-velocity impact analysis of camel hair and hybrid camel hair/flax fibre-reinforced epoxy
    (Springer, 2024) Bencheikh, Amir; Nour, Abdelkader; Casimir, Jean B.; Aguib, Salah; Gherbi, Mohammed T.; Attia, Nourhane; Djedid, Toufik; Baali, Besma. R.; Aribi, Chouaib
    Composite plates structures are subjected to many damage problems under low-velocity impacts such delamination and matrix cracking, in order to know the importance of hybridisation on improving mechanical properties. This study explores the low-velocity impact behaviour of two composites: one reinforced with camel hair fibre/epoxy (CHF/Epoxy) and the other with a hybrid of camel hair and flax fibres camel hair fibre–flax fibre/epoxy (CHF-Flax/Epoxy). Static tests (tensile, compression, and bending) were conducted to characterise the mechanical properties of the composites. Impact tests were performed using a drop weight impact machine at three energy levels (3, 7, and 20 J). Particularly, the hybrid composite plate (camel hair fibre/epoxy) exhibited superior mechanical properties in static tests, leading to enhanced impact resistance compared to the composite plate (camel hair fibre/epoxy). Additionally, a numerical study was conducted using a 3D finite elements model. The Hashin criteria and the progressive damage model were used to predict intralaminar damage, and surface-based cohesive behaviour with quadratic stress failure criteria was used to predict delamination. The progressive damage model was coded and its implementation is conducted with a user-defined material subroutine (VUMAT) for Abaqus/Explicit. The damage mechanism and energy dissipation were observed at each energy level. Matrix cracking occurred first, followed by delamination. The 3D damage model was able to simulate the damage initiation and damage evolution until failure. The results of the model showed good agreement with experimental results in term of force, displacement and energy dissipation curves.
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    Impact Behavior Analysis of Luffa/Epoxy Composites Under Low-Velocity Loading
    (Springer Nature, 2024) Grabi, Massinissa; Chellil, Ahmed; Lecheb, Samir; Grabi, Hocine; Nour, Abdelkader
    Luffa cylindrical (LC) has an exceptionally multipartite architecture, a hierarchical and light structure, and a low density. Such a structure is potentially suitable to replace conventional porous-type composites for low-energy absorption and material reinforcement applications. This paper presents an experimental study of the impact behavior of four different luffa/epoxy composites, named (A), (B), (C), and (D) subjected to low-velocity impact (LVI) at energies ranging from barely visible impact damage (BVID) to perforation (5,15, and 20J). Acoustic emission (AE), scanning electron microscopy (SEM), and digital image correlation (DIC) were introduced to the indentation test to offer additional information on damage mechanisms and on strain and displacement fields since the LVI test has a short duration and real-time damage monitoring is not always achievable. The results showed that the values of the peak force of laminates (A), (B), and (D) are relatively lower compared to laminates (C). In the case of perforation impact energy (20J), the Coefficients of Restitution (CoR) of composites (A), (B), and (D) are equal to 0, which indicates that the nature of the impact is completely plastic, except for composite (C) had a value of 0.11, and a lower degree of damage at all impact energies. Composites (C) exhibit the highest impact resistance, followed by composites (A), while composites (D) display the highest energy absorption, followed by composites (B). Multivariable statistical analysis of the AE signals identified four classes of damage: matrix cracking, fiber-matrix debonding, delamination, and fiber breakage. The damage modes found by AE are well presented and proven by SEM analysis. The luffa fiber-reinforced composite has better impact properties than other natural fiber-reinforced composites.
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    Dynamic characterization of the magnetomechanical properties of off axis anisotropic magnetorheological elastomer
    (De Gruyter Open, 2022) Bendjeddou, Walid; Aguib, Salah; Chikh, Noureddine; Nour, Abdelkader; Djedid, Toufik; Kobzili, Lallia; Meloussi, Mounir
    The use of magnetorheological elastomers in the mechanical and acoustic fields, by the automotive, aeronautical, and building industries, is currently developing strongly and rapidly. The perfect understanding of the capacity of smart insulation based on the absorption of the vibratory waves by magnetorheological elastomers materials passes by the knowledge of their dynamic mechanical behavior. In this present work, we have characterized the dynamic mechanical properties of the magnetorheological elastomer off axes anisotropy by the inclination, of different angles (15°, 30°, and 45°), of the pseudo-fibers of the iron particles formed by the application of a magnetic field at different intensities using an optimal loading rate of 30%. The rubber specimens were prepared by mixing micron-sized iron particles dispersed in room temperature vulcanized (RTV) silicone rubber by solution mixing. The experimental results obtained show a clear dependence of the effect of inclusion of ferromagnetic chains on the magnetomechanical properties. It is observed that the mechanical properties are better when applying a magnetic field of 0.6 T with an angle of inclination of 45°. The improvements added in this work could be useful in several industrial applications, such as automotive, aeronautic through adaptive control of damping and vibration level
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    Measurements and identification of smart magnetomechanical elastomer composite materials properties in shear mode
    (Institute of Physics Publishing, 2019) Nedjar, Ali; Aguib, Salah; Djedid, Toufik; Nour, Abdelkader; Meloussi, Mounir
    Magnetorheological elastomer composite materials (MRE) are a new class of intelligent active materials composed of ferromagnetic particles, of micrometric size, dispersed in a silicone elastomer matrix, which exhibit variable stiffness and damping properties which are modifiable under the application of an external magnetic field. Currently, these devices are primarily used in automotive and building applications, but they can easily be adapted to meet the requirements of aerospace applications. The development process and experimental characterization needed to evaluate the active control performance of this material have been made. This is done by characterizing the mechanical properties as a function of the magnetic field, as a function of the excitation frequency and as a function of the different percentage of ferromagnetic particles loading. An example of application of this material in aeronautics is also presented
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    Reproducing kernel Hilbert space method for the numerical solutions of fractional cancer tumor models
    (2020) Attia, Nourhane; Akgül, Ali; Seba, Djamila; Nour, Abdelkader
    This research work is concerned with the new numerical solutions of some essential fractional cancer tumor models, which are investigated by using reproducing kernel Hilbert space method (RKHSM). The most valuable advantage of the RKHSM is its ease of use and its quick calculation to obtain the numerical solutions of the considered problem. We make use of the Caputo fractional derivative. Our main tools are reproducing kernel theory, some important Hilbert spaces, and a normal basis. We illustrate the high competency and capacity of the suggested approach through the convergence analysis. The computational results clearly show the superior performance of the RKHSM.
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    An efficient numerical technique for a biological population model of fractional order
    (ELSEVIER, 2021) Attia, Nourhane; Akgül, Ali; Seba, Djamila; Nour, Abdelkader
    In the present paper, a biological population model of fractional order (FBPM) with one carrying capacity has been examined with the help of reproducing kernel Hilbert space method (RKHSM). This important fractional model arises in many applications in computational biology. It is worth noting that, the considered FBPM is used to provide the changes that is made on the densities of the predator and prey populations by the fractional derivative. The technique employed to construct new numerical solutions for the FBPM which is considered of a system of two nonlinear fractional ordinary differential equations (FODEs). In the proposed investigation, the utilised fractional derivative is the Caputo derivative. The most valuable advantages of the RKHSM is that it is easily and fast implemented method. The solution methodology is based on the use of two important Hilbert spaces, as well as on the construction of a normal basis through the use of Gram-Schmidt orthogonalization process. We illustrate the high competency and capacity of the suggested approach through the convergence analysis. The computational results, which are compared with the homotopy perturbation Sumudu transform method (HPSTM), clearly show: On the one hand, the effect of the fractional derivative in the obtained outcomes, and on the other hand, the great agreement between the mentioned methods, also the superior performance of the RKHSM. The numerical computational are presented in illustrated graphically to show the variations of the predator and prey populations for various fractional order derivatives and with respect to time.
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    On solutions of time‐fractional advection–diffusion equation
    (WILEY ONLINE Library, 2020) Attia, Nourhane; Akgül, Ali; Seba, Djamila; Nour, Abdelkader
    In this paper, we present an attractive reliable numerical approach to find an approximate solution of the time‐fractional advection–diffusion equation (FADE) under the Atangana–Baleanu derivative in Caputo sense (ABC) with Mittag–Leffler kernel. The analytic and approximate solutions of FADE have been determined by using reproducing kernel Hilbert space method (RKHSM). The most valuable advantage of the RKHSM is its ease of use and its quick calculation to obtain the numerical solution of the FADE. Our main tools are reproducing kernel theory, some important Hilbert spaces, and a normal basis. The convergence analysis of the RKHSM is studied. The computational results are compared with other results of an appropriate iterative scheme and also by using specific examples, these results clearly show: On the one hand, the effect of the ABC‐fractional derivative with the Mittag–Leffler kernel in the obtained outcomes, and on the other hand, the superior performance of the RKHSM. From a numerical viewpoint, the RKHSM provides the solution's representation in a convergent series. Furthermore, the obtained results elucidate that the proposed approach gives highly accurate outcomes. It is worthy to observe that the numerical results of the specific examples show the efficiency and convenience of the RKHSM for dealing with various fractional problems emerging in the physical environment.