Université Mouloud Mammeri de Tizi Ouzou (UMMTO): Research Review of Sciences and Technologies
Not a member yet
2222 research outputs found
Sort by
Using optimization algorithms to detect damages on free-free beam based on dynamic results
Get PDFThis article describes a Modal Analysis method for detecting damage in free-free beams using natural frequency data. The method involves updating a numerical model of the beam with experimental or reference natural frequencies to determine the damage location and damage index. The accuracy of the method was verified through simulations and experiments on beams with both single and double damage zones. The results demonstrate that the method is effective in detecting the damage location for single damage zone and double damage zones with the same or different damage index. However, when the two damage zones are close together, the method that updates the model through PSO optimization algorithm using the reference frequency data may produce inaccurate results. Furthermore, when using experimental frequency data for damage beams, the results indicate that the method has a damage location error of approximately 3.5% along the entire beam length, which is considered acceptable in practical applications. The natural frequency-based damage detection method described in this article offers a useful tool for the assessment of damage in free-free beams and can be effectively combined with visual inspection techniques
Effets de la caractérisation probabiliste des paramètres du sol et de l’ISS sur la vulnérabilité sismique d'une structure en béton armé
Get PDFThis article targets two objectives: to identify the most influential sources of uncertainty by analyzing the effects of the probabilistic characterization of two soil parameters on the soil-structure interaction system. The second is to determine the seismic fragility curves of a structure by considering the epistemic uncertainty due to the correlation between and . To achieve these objectives, a 9-story reinforced concrete structure was studied considering different soil types. The analysis of the results showed that the influence of the correlation coefficient and the coefficient of variation are not the same for all soil types. Indeed, these coefficients play a major role in estimating the structural response for very soft soils, which is less true for soft, hard and rocky soils. It has also been shown that epistemic uncertainty plays the most important role in damage assessment.Cet article cible deux objectifs : à identifier les sources d'incertitudes les plus influentes en analysant les effets de la caractérisation probabiliste de deux paramètres du sol sur le système interaction sol-structure. Le deuxième est de déterminer les courbes de fragilité sismique d'une structure en considérant l'incertitude épistémique due à la corrélation entre et . Pour atteindre ces objectifs, une structure en béton armé de 9 étages a été étudiée en considérant différents types de sols. L'analyse des résultats a montré que l’influence du coefficient de corrélation et du coefficient de variation ne sont pas les mêmes pour tous les types de sols. En effet, ces coefficients jouent un rôle majeur dans l’estimation de la réponse structurelle pour les sols très meubles, ce qui est moins vrai pour les sols meubles, durs et rocheux. Il a également été démontré que l’incertitude épistémique joue le rôle le plus important dans l’évaluation des dommages
Advanced Composite Materials and Structures
Get PDFComposite materials are used to produce multi-objective structures such as fluid reservoirs, transmission pipes, heat exchangers, pressure vessels due to high strength and stiffness to density ratios and improved corrosion resistance. The mathematical concepts can be used to simulate and analyze the generated mechanical and thermal properties of composite materials regarding to the desired performances in actual working conditions. To solve and obtain the exact solution of the developed nonlinear differential equations in the composite materials, analytical methods can be applied. Mechanical and thermal analysis of complex composite structures can be numerically analyzed using the Finite Element Method (FEM) to increase performances of composite structures in different working conditions. To decrease failure rate and increase performances of composite structures under complex loading system, thermal stress and effects of static and dynamic loads on the designed shapes of composite structures can be analytically investigated. The stresses and deformation of the composite materials under the complex applied loads can be calculated by using the FEM method in order to be used in terms of safety enhancement of composite structures. To increase the safety level as well as performances of the composite structures in different working conditions, crack development in elastic composites can be simulated and analyzed. To develop and optimize the process of composite deigning in terms of mechanical as well as thermal properties under different mechanical and thermal loading conditions, the advanced machine learning systems can be applied. A review in recent development of composite materials and structures is presented in the study and future research works are also suggested. Thus, to increase performances of composite materials and structures under complex loading systems, advanced methodology of composite designing and modification procedures can be provided by reviewing and assessing recent achievements in the published papers
A Numerical Simulation Approach for Investigation of the Pressure Coefficient on the Main Building at the Hill’s Top Under the Interference.
Get PDFThe majority of the time, existing codes and standards are used to predict wind loads on structures. The criteria of these standards are based on a wind tunnel test that was done on a single building. On the other hand, buildings rarely stand alone. Wind loads on the principal building are increased or decreased as a result of interference effects caused by interfering buildings. A numerical simulation using ANSYS Fluent 2020 R1 is used in this research to investigate the impact on wind pressure on main building under the interference condition on the hill's top. The external average pressure coefficient on main building on hill’s top are determined in the presence of interfering building with varying height ratios of 0.5, 0.75, 1.0, and 1.25, and spacing to width ratios of 0.5, 1.0, 1.5, and 2.0 on 3-D hill. The pressure coefficient decreases as the height of the interfering building rises, showing an increase in the shielding effects of the structure in the vicinity. Nevertheless, when the height of the interfering building is 0.5 of the height of the main building, it is found that the shielding effect has a significant impact on the main building. Because of its placement at the top of the hill, found a significant difference in the pressure coefficient on the rear face of the main building
Analysis, Behavior, Strengthening and repairing of Reinforced Concrete Corbels: Comprehensive Review
Get PDFIn this review, an extensive survey on the theoretical models and approaches that were proposed in literature to study the behavior of RC corbels has been presented. Such approaches included the shear friction approach, strut and tie model, finite element and Neural networks. Moreover, the review has been extended to consider the studies conducted experimentally by researchers and scholars to investigate the response of the RC corbels. Furthermore, various proposals that were suggested regarding strengthening and repairing of RC corbels have been discussed. Different materials have been used to improve the performance of RC corbels, such as steel fibers, FRP composites, NSM steel bars, NSM CFRP bars and composite sections have been considered. The most important findings reported in the relevant literature have been summarized. In addition, several recommendations to extend the studies concerning the RC corbel to improve the knowledge about the behavior of this significant structural member have been presented
الثورة التحريرية الجزائرية: من السرد الروائي إلى التصوير السينمائي. "العفيون والعصا" لـ "مولود معمري" و"ذاكرة الجسد" لـ "أحلام مستغانمي" أنموذجا.
No full textThe Algerian liberation revolution has known events that remain firmly in the memory of all Algerians and this is clearly manifested in the narrative texts and cinematographic works presented by writers and filmmakers. cinema has become an image of the novel which fulfills an aesthetic and communicative function and the cinematographic.Quotation has come to perpetuate the distinction of narrative texts in its transmission from the place of the revolution represents an act which improves collective memory, literature and art provide a copy of the revolution in all its dimensions, whether by listing the acts of bravery and the cruelty of the war of liberation as well as the nobility of the sacrifice for the good of the fatherland, but this adaptation has an aesthetic function and records the participation of art and literature in a distinctive glorification of the revolution. however, this transfer from the novel to the cinema requires touching the mechanisms of transmission of stories and embodying them in cinematographic films and revealing the paradoxes that result from the interaction between the novel and the film. and this is what we will approach in detail through this study, based on two models which are the novel of opium of Mouloud Mammeri, and the novel "memory of the body" by Ahlam Mostaghanemi and, their cinema adaptation.
Modelling the Viscoelastic Behavior of asphalt Concrete at the Nanoscale
Get PDFThe main purpose of this paper is to investigate the mechanical properties “hardness H and elastic modulus E” of asphalt concrete AC at the nanoscale to get its mechanical behavior comparing to the distinct behaviors of its different phases got from experimental works. AC is generally composed of coarse aggregates that have an elastic mechanical behavior, a viscoelastic or viscoplastic binder and interface transition zone ITZ. For this; as bituminous material we have used an asphalt concrete sample which is subjected to a nanoindentation simulation test using a Berkovich indenter tip with a load of 2500 µN for 10 s of loading and 10 s of unloading. AC is supposed to be a viscoelastic material; so the Prony series are introduced and different coefficients of prony are obtained from an experimental relaxation’s master curve of AC. Finite element software ABAQUS 6.13 is used to simulate this mechanical behavior where our study is carried out at a temperature of 25°C. The results showed that hardness and young’s modulus values are closer to the aggregates phase than to the fine matrix results, in other words it seems that our asphalt concretes responds of an elastic behavior at the nanoscale
Assessment fairness and the different Sources of Assessment Bias at the Algerian University Level
Get PDFThe present work tries to shed light on a critical, but neglected aspect of assessment design and delivery in the Algerian context. Indeed, many teachers are so accustomed to deliver tests and exams that they do it mechanically without thinking about their possible negative ethical effect on students’ performances. Among these aspects, one can highlight the different types of assessment bias that tests can carry and that can interfere in the students’ performances. Assessment bias or the lack of fairness on the part of the assessors are due to different causes. The present article attempts to unveil two of its main sources such as tests’ deign bias and the bias caused by assessors’ ignorance of the learners’ differences such as cultural bias, cognitive differences and the different degrees of learners’ tolerance to ambiguity
التخيل التاريخي واستدعاء الذاكرة في رواية "الديوان الإسبرطي" لعبد الوهاب عيساوي
Get PDFThe contemporary world is witnessing an increasing interest in history and memory’s issues, and this was reflected in a novelist way of writing that questions history and digs into the corridors of memory. The Algerian novel has become involved in this direction, as we note recently that novelists have focused on recent and less close history with different visions of the perceptions about the past, such as the novel “Addiwan al-Isparti” by Abdel-Wahab Aissaoui, which stood at the time of France’s invasion of Algeria and the expulsion of the Ottomans from it.This study aims to shed light on the interactions of history and memory on both the theoretical and practical levels. The adoption of the term "historical imagination" to express the fragility of the boundaries between history and the novel, on the other hand, the redefinition of history led to an escalation of interest in memory in historical and literary studies, as the novel became an important mediator of memory.In the second part, we analyzed the recall of memory and historical reference. In the narration studied at the level of thresholds discourse, and the polyphonic narrative structure that allows multiple memories, we devoted methods of intertextuality (Diaries, Lettres, etc.), historical intertextuality and margin memory
فن المانجا الياباني- مقاربة بلاغية-
No full textThe article aims to ask the question: What is next after Western literature and rhetoric? He believes that the answer is Eastern etiquette and rhetoric, which are marginalized by Western rhetoric. Not for its impotence and poverty, but rather for its political and economic consequences and the negative image that the West drew about the East and the struggle with it this fabricated throughout history. The East has always been the source of the spiritual sciences of the East. Ancient Japanese art, but now it is invading the West and finding great demand for it.The research concluded that objective scholarly rhetoric requires that Arabic rhetoric combine literature with oriental rhetoric and western rhetoric, the latter being a product of Greek philosophy, it has been proven that this philosophy is stolen eastern philosophy, so Western rhetoric is rhetoric of eastern origin, and the combination of western rhetoric and eastern rhetoric establishes a universal rhetoric