Browsing by Author "Sid Amer, Youcef"

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Analyse de la fiabilité structurelle et conception de réservoirs composites de stockage d'hydrogène
(Université M'Hamed Bougara Boumerdès : Faculté de Technologie, 2024) Sid Amer, Youcef; Benammar, Samir(Directeur de thèse)
L’object if de cette thèse est l’analyse de la fiabilité et la conception de réservoirs composites de stockage d’hydrogène à haute pression. Pour ce faire, deux approches ont été adoptées : dans le premier cas, la méthode de Monte Carlo est utilisée pour analyser les distributions des marges de sécurité et illustrer la variabilité de la réponse mécanique de la structure en fonction de plusieurs paramètres de conception. Dans le deuxième cas, la méthode de Subset Simulation est employée pour développer un cadre de calcul permettant la quantification des très petites probabilités de défaillance des réservoirs composites de stockage d’hydrogène à haute pression. L’étude a montré la faisabilité et la précision de ces deux méthodes dans la prédict ion de la pression d'éclatement. En outre, l’étude a révélé que les incertitudes associées à la pression interne et à l'épaisseur des couches circonférentielles affectent de manière significative la fiabilité de la structure et peuvent conduire à une réduction de la marge de sécurité et à la défaillance du réservoir
A contribution to structural reliability analysis of composite high-pressure hydrogen storage tanks
(KONBiN, 2023) Sid Amer, Youcef; Benammar, Samir; Fah tee, Kong; Wadi, Mohammed; S. Jouda, Mohammed
Although composite high-pressure tanks are a subject of growing interest, especially for hydrogen storage applications, a detailed structural reliability analysis still needs to be improved. This work aims to provide a probabilistic investigation of the mechanical response of composite high-pressure hydrogen storage tanks using the Monte Carlo Simulation method. A performance function based on the circumferential model of composite pressure cylinders is employed with five random design variables. According to the results, the internal pressure and the helical layer thickness are the foremost parameters significantly impacting the structural reliability of the tank, whereas, the helical layer thickness and winding angles have a minor influence. In addition, high coefficients of variation values cause the contraction of the safety margin potentially leading to the failure of the composite hydrogen high-pressure tank. The obtained results were validated with experimental tests available in the literature.
Failure Probability Analysis of Composite Pressure Tanks Using Subset Simulation
(Semnan University, Faculty of Mechanical Engineering, 2024) Sid Amer, Youcef; Benammar, Samir; Tee, Kong Fah; Iourzikene, Zouhir
Composite pressure tanks have received increased attention across a number of civilian applications due to their lightweight and high strength. Traditionally, the design of composite vessels is based on deterministic analysis. However, the design of these structures is challenging and involves several kinds of uncertainties. In fact, different computational investigations have been carried out but no studies provide a resolution for small failure probability evaluation of composite pressure tanks. The aim of this study is to establish a computational framework to investigate small failure probability levels of composite tanks using the Subset Simulation method (SS). The model was developed in two steps, first, the development of limit state functions for hoop and helical layers using netting analysis, and afterwards, a probabilistic computation with six random variables. To quantify the effect of the randomness of different parameters on the structural reliability of composite tanks, a sensitivity analysis was performed using different values of coefficients of variation (COV). It was observed from the results that SS has the ability and the accuracy required to evaluate small failure probabilities which are commonly encountered in composite tank applications. In addition, the hoop strength, the internal pressure, and the thickness of the composite are the major design variables that have a great impact on the structural reliability of the axially symmetric composite tank whereas the fiber winding angle has little effect. Moreover, high COV values drastically reduce the safety zone, which could eventually lead to the burst failure of the composite pressure tank. Furthermore, this study implements a reliability-based design from the perspective of hoop and helical composite layer thicknesses, thus providing a rational assessment of the risk of structural failure.
Sustainable composite materials with date palm rachis fibers for enhanced insulation and structural integrity
(Institute of Physics, 2024) Ferhat, Maroua; Djemai, Hocine; Guettaf Temam, Elhachmi; Labed, Adnane; Lahag, Lemya; Sid Amer, Youcef
This investigation focuses on the development and characterization of sustainable composite materials for insulation and structural components in the automotive and shipbuilding industries, by incorporating date palm Rachis fibers into an epoxy matrix. Thus, we evaluated the effect of the weight ratio (ranging from 0 to 15 wt%) of Rachis fibers (0.315 mm) on the mechanical, physical, surface morphology, thermal properties, and water absorption. It turns out according to the study that, the XRD pattern revealed the amorphous nature of the composite. This new material can be used as composite material itself or as a skin of a sandwich composite material. The Epoxy-Rachis (ER) composite materials exhibited a low thermal conductivity of 0.21 W/ (m.K) and a low thermal diffusivity of 0.17 mm2 s−1 presenting high thermal insulation and construction properties. The SEM images showed that increasing Rachis fiber concentration produces a heterogeneous bio-composite material. The resulting composition showcases ductile fracture behavior with a flexural modulus (Ef) of 3.21 GPa and a bending strength (σ) of 9.28 MPa. These attributes underline the suitability of this composite for applications requiring efficient thermal insulation and robust construction properties, while simultaneously contributing to environmental sustainability and environmental benefits.