Optimization of Ultimate Tensile Strength with DOE Approach for Application FSW Process in the Aluminum alloys AA6061-T651 & AA7075 -T651

As it is imperative to control the materials development processes well, in parallel, it will be necessary to constantly adapt very efficient assembly methods. Friction stir welding makes it much easier for us to fusion the aluminum alloys like AA6061-T651 and AA7075 -T651. But we noted the difficulty of containing its many parameters such as the welding speed, the rotation speed and the type of pin used during the operation to optimize mechanical properties and in particular to obtain high rupture strength with the tensile test. This why in this paper we treat carefully this process in order to define it drastically, by using the design of experiment method which is an original approach that resides in the possibility of interpretation of experimental results with a minimal effort on the experimental level whichever generates the minimization of the necessary number of experiments and allows a saving in time and in financial cost

Admissibility of External Cracks in a Pipeline API X60 Using the SINTAP Procedure

In this paper we tried to apply the failure assessment diagram method on an API X60 pipeline under two pressures 70 and 90 bar, this work will be divided into two parts; the first part will be devoted to modeling and simulation of a pipeline under pressure 70/90 bar. With abaqus software to determine the stress intensity factor of several ratios, The second part will focus on the exploitation of these results in order to draw the diagram of evaluation of the failure (FAD), once finished, We can pronounce on the vulnerability of the cracks which can cause the ruin of the pipeline to study, on mode of ruin and proposed safety factors

Artificial Neural Network Active Power Filter with Immunity in Distributed Generation

With an electrical grid shifting toward Distributed Generation (DG), the emerging use of renewable energy resources is continuously creating challenges to maintain an acceptable electrical power quality thought-out the grid; Therefore, in an energy market where loads are becoming more and more sensitive in a distributed generation filled with polluting nonlinear loads, power quality improvement devices such Active Power Filters (APFs) have to evolve to meet the new standards, since theirs conventional control strategies can't properly operate when multiple power quality problems happens at once, even the one using AI based control as it will be proven in this paper. In this paper a neural network based Active Power Filter will be tested in a DG environment where both current and voltage harmonics, along with fast frequency variation occurs, we will see how the PLL can downgrade its performances enormously under such hostile conditions, We propose to solve this problem by replacing the conventional PLL with a nonlinear least square (NLS) frequency estimator, this novel NLS-ADALINE SAPF is immune in high DG penetration environment, as it will be tested and validated experimentally on an Opal-RT OP5600 FPGA based real-time simulator

An Interactive Method to Analysis of the Response of the Different Reinforcement Structures of a Door Opening of a Wind Tower

The aim of this work is to present a precise numerical calculus method capable to predict the behavior of a wind turbine mast, which is characterized by an open door in its lower part in order to facilitate the access to maintenance tasks. A parametric study had been conducted in this context. The structure studied of steel tower is considered a thin cylindrical shell with constant section and thickness along its studied height. The geometry of the tower had been modeled by non-linear shell type elements. Designers use interior reinforcements to avoid local buckling and minimize the disturbance of the distribution of stress in extreme conditions. The designs adopted in the models are proposed to achieve optimized results, the minimization of the mass, the maximization of the natural frequency and the rigidity at the end of the work. Many configuration had been considered in this study, the enhancement of the gap by using a panel with variable thickness value, by longitudinal stiffeners, by combined stiffeners and finally by a stiffened panel. A numerical model had been suggested to examine a cylindrical shell behavior in compression using the Abaqus software. The obtained results demonstrate the viability and performance of the proposed approach which perfectly meets the structural requirements of the wind tower. We have observed that the stiff plate model gives reliable results to stability under extreme load. On the other hand it is economically profitable is less material needed for manufacturing, which reduces the cost

Effect of lid height and blowing ratio on film cooling effectiveness of a novel lidded hole configuration

Film cooling is one of the promising technologies used for protecting rocket nozzles and turbine blades from combustion chamber hot gases. This paper proposes a novel shape of film cooling injection hole, called lidded hole, that can offer significant enhancement of cooling performance. ANSYS CFX is used to perform 3D numerical simulations of a flat plate with a single row of lidded holes, in which the k–ε model approximates turbulence effects. Four cases are investigated to highlight the influence of the hole's lid height (H/d = 0, 0.25, 0.5, 0.75). The effect of blowing ratios (M = 0.5, 1, 1.5) is also analyzed for each configuration. The numerical results of this study are compared with available experimental data, and, generally, a good agreement is achieved. The results obtained show that the lidded hole configuration reduces the coolant flow separation which improves significantly the film cooling effectiveness. In addition, increasing the blowing ratio leads to an increase in lateral and centerline cooling effectiveness. Comparing all studied cases, the optimum coolant coverage was obtained for the lidded hole configuration with H/d = 0.25 at M = 1.5

Study of the attitudes of individuals towards dealing with Islamic banks, the Case of Al Baraka ‎Bank clients.‎

يتناول هذا البحث المصارف الإسلامية التي بدأت تتنامى وتطرح نفسها كبديل في مختلف دولالعالم، وبدأ مؤيدوها في تزايد مستمر، وذلك من خلال محاولة معرفة اتجاهات الأفراد للتعامل معهذا النوع من المؤسسات المالية، مستعملين في ذلك المنهج الوصفي التحليلي ومنهج دراسة الحالة ،وذلك في ثلاثة محاور أساسية هي: التعريف باتجاهات الأفراد ثم التعريف بالمصارف الإسلامية وأخيرادراسة ميدانية حول اتجاهات الأفراد نحو بنك البركة الجزائري كنموذج للدراسة.This research of Islamic banks, which began growing and presents itself as an alternative in the various countries of the world, and began her supporters continues to increase, through trying to figure out trends individuals to deal with this type of financial institutions, using the descriptive analytical approach and the methodology of the case study, and in three basic axes: definition individuals directions and then the definition of Islamic banks and finally a field study on the attitudes of individuals towards the Algerian Al Baraka Bank as a model for the study

Parametric study of the ductile damage by the Gurson–Tvergaard–Needleman model of structures in carbon steel A48-AP

This part of study is devoted to the numerical simulation of axisymmetric notched specimens in order to study the phenomenon of nucleation by Gurson–Tvergaard–Needleman model (GTN). The numerical simulations were performed to describe the damage of the materials using GTN model, which involves the stress triaxiality. The specimens chosen are somewhat axisymmetric notched (AN): hence, this choice was motivated by the symmetry of these specimens, and also by the existence of notches that make them interesting in the case of fracture mechanics

On Sustaining Dynamic Adaptation of Context-Aware Services

The modern human is getting more and more mobile having access to online services by using mobile cutting-edge computational devices. In the last decade, the field of context-aware services had led to emerge several works. However, most of the proposed approaches have not provided clear adaptation strategies in case of unforeseen contexts. Dealing with this last at runtime is also another crucial need that has been ignored in their proposals. This paper aims to propose a generic dynamic adaptation process as a phase in a model-driven development life-cycle for context-aware services using the MAPE-K control loop to meet the runtime adaptation. This process is validated by implementing an illustrative application on FraSCAti platform. The main benefit of the proposed process is to sustain the self-reconfiguration of such services at model and code levels by enabling successive dynamic adaptations depending on the changing context