Génie mécanique
Permanent URI for this collection
Browse
Recent Submissions
Item Tolerance Synthesis of Delta-like Parallel Robots Using a Nonlinear Optimisation Method(Applied Sciences, 2023-07-26) Allaoua Brahmia; Adlen Kerboua; Ridha Kelaiaia; Ameur LatrecheRobotic systems require high accuracy in manipulating objects. Positioning errors are influenced by geometric tolerances and various sources. This paper introduces a new technique based on the interior-point algorithm optimisation method to allocate tolerances to the geometric parameters of a robot. This method consists of three steps. First, a method for modelling the kinematic problem as well as the geometric errors must be used. The Denavit–Hartenberg rule is the most suitable method for this modelling case. Then, a mathematical model for tolerance allocation is developed and used as a nonlinear multivariable optimisation problem. Finally, the “interior-point” algorithm is used to solve this optimisation problem. The accuracy and efficiency of the proposed method, in determining the tolerance allocations for a Delta parallel robot, is illustrated via calculation and simulation results. The values of the dimensional tolerances found are optimal. As a result, these values always keep the accuracy less than or equal to the imposed value.Item Weibull Statistic and Artificial Neural Network Analysis of the Mechanical Performances of Fibers from the Flower Agave Plant for Eco-Friendly Green Composites(JOURNAL OF NATURAL FIBERS, 2024-01) Lalaymia Imen; Belaadi Ahmed; Boumaaza Messaouda; Alshahrani HassanThe research conducted focused on examining the unique properties of Agave Americana Flower Stem fiber (AAFS), particularly its behavior under quasi-static tensile conditions. A total of 200 AAFS fibers were subjected to tensile tests using a standard gauge length of 40 mm. Tests spanned seven groups with quantities (N) ranging from 30 to 200. The study aimed to understand the fibers’ mechanical traits, as tensile resistance and modulus of elasticity, and to see how different test quantities influence these properties. A significant observation was the dispersion of the tensile characteristics of AAFS fibers, a common trait of natural fibers. To understand this, we applied rigorous statistical tools, including the Weibull distribution at a 95% confidence interval and one-way ANOVA. A mathematical model was produced utilizing data from experiments regarding the tensile behavior of AAFS fibers. The ANN provided correlation coefficients (R2 ) of 0.9897, 0.9971, 0.9993, and 0.9939 for training, validation, testing, and all datasets respectively, which were able to accurately predict the experimental data. The proposed model would be of tremendous assistance to engineers and designers in obtaining green composite materials that are based on natural fibers and thereby more durable. These methods illuminated the patterns in our results, enriching our understanding of AAFS fiber mechanicsItem Increment of heat transfer by graphene-oxide and molybdenum-disulfide nanoparticles in ethylene glycol solution as working nanofluid in penetrable moveable longitudinal fin(Waves in Random and Complex Media, 2022-01-31) Talbi Nabil; Kezzar Mohamed; Malaver Manuel; Tabet IsmailThe main interest of the current research study is, on the one hand, to increase heat transfer of the base and mixture fluids by using hybrid nanoparticles. By considering two types of boundary conditions such as insulated and convective tips, to explore numerically and analytically the simultaneous impacts of the thermal radiative and free convective flow of hybrid nanofluid via a moving porous longitudinal fin. This investigation employs Darcy’s model and the mixture base fluid H2O (50%)–C2H6O2 (50%). The governing equations have been solved by utilizing Runge–Kutta–Fehlberg 4th–5th order technique (RKFT45) with shooting-scheme and analytically via Duan–Rach Approach (DRA). It is found that the nondimensional temperature θ (η) is a decreasing function of a wet porous number m2 and convective parameter Nc for both insulated and convective tips, and as an increasing function of ambient temperature θa, Peclet number Pe and power index n. It is also found that the thermal profile θ (η) presents a decrease for all considered shape factors in the cases of insulated and convective tips boundary conditions. Computational results and those obtainable in the previous works have been used to verify and strengthen the results gained by the analytical DRA technique.Item Faults Diagnosis in PV Systems Using Structured Residuals and Indicator Parameters Techniques(Journal Européen des Systèmes Automatisés, 2023-04-05) Boukoffa Kamel; Metatla Abderrezak; Louahem Msabah Ilyes; Benzahioul SamiaThe detection and identification of some types of faults in PV systems is often difficult, because it is not possible to distinguish the noise coming from external factors and the influence of some faults on the parameters generated by PV systems. Until today, scientific works have focused more on the detection and identification of faults affecting a PV system. These works are focused on the application of different sophisticated and unsophisticated techniques. Therefore, the possibility of obtaining significant information about faults requires the development of more advanced techniques. The presented work consists of studying the influence of defects on the behavior of a photovoltaic system. In the first part, the work aims to present a signal processing technique based on the analysis of structured residual. In the first step of this part, the generated currents by the GPV are presented with the three operating modes: healthy, shading fault and progressive resistance fault, in the second step, the prediction errors of the current vectors from the three operating scenarios of the GPV are calculated. The evaluation of the developed approach, shows the efficiency and the identification precision of this method. In the second part, a technique based on the SEA method (Shape exchange algorithm) is presented whose diagnostic indicators were calculated, these indicators were classified according to their degree of criticality into three main categories. The obtained results show the effectiveness of this technique and the possibility of further increasing the detection and identification performance of faults in the PV system.Item A Techno-Economic Study of a Hybrid PV-Wind-Diesel Stand-Alone Power System for a Rural Telecommunication Station in Northeast Algeria †(Engineering proceedings, 2023-10-27) Zegueur Ahlem; Sebbagh Toufik; Metatla AbderrezakTelecommunication stations, particularly operating in rural areas are usually powered by diesel generators due to the lack of access to the utility grid. However, the growing cost of energy due to the constantly increasing fuel prices and the related greenhouse gas emissions contributing to the global warming have driven the telecom companies to seek for better energy management solutions. In this paper, we study the economic feasibility of an environmentally friendly power supply system for rural telecommunication station in the city of Skikda, northeast Algeria. The proposed system is a standalone hybrid PV-Wind system with pre-existing diesel generators and battery storage. Different system configurations are considered in the study: (a) Diesel generators only, (b) PV-Diesel-battery, (c) Wind-Diesel-Battery, (d) PV-Wind-Diesel-Battery, and lastly (d) PV-WindBattery, this helps to select the most optimal solution based on the lowest net present cost (NPC) and the cost of energy (COE) of each configuration. The optimization is performed using HOMER PRO software. The results showed that a hybrid system of 5 kW DG, 3.81 kW of PV capacity, 3 wind turbines and 14 battery bank is the best design for the proposed power system with an NPC of 85,673 $ and a COE of 0.214 $. The greenhouse gas emissions were considerably reduced to more than half making the proposed system a technically, economically and environmentally viable solution.