4,386 research outputs found

    Manufacturing Process Modeling and Simulation

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    This paper presents a methodology to be employed in the whole process design phase including first and second processing. This methodology consists of a set of steps which are characterised by an independent model. This paper’s objective is to analyse the coherence between the different models and the coherence between the model and the objectives of each step. The final stage is to develop the production plans. The casting process was the first one to be analyzed. Casting models were created using CAD software (Catia V5R17) and imported into the casting simulation environment (Magmasoft). Filling and solidifying processes have been simulated using different casting models in order to optimize the final configuration. The machining process was modeled using the machining features concept and it was simulated using Catia’s Advanced Machining environment. Two machining strategies have been analyzed according to positioning strategies. Process engineering software was used to create the process plans and to analyze the resource allocation

    An improved firefly algorithm for optimal microgrid operation with renewable energy

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    Lately, an electrical network in microgrid system becomes very important to rural or remote areas without connection from primary power grid system. Higher cost of fuels, logistic, spare parts and maintenance affect the cost for operation microgrid generation to supply electrical power for remote areas and rural community. This project proposes an Improved Firefly Algorithm (IFA), which is a improvement of classical Firefly Algorithm (FA) technique using characteristic approach of Lévy flights to solve the optimal microgrid operation. The IFA has been used for optimizing the cost of power generation in microgrid system where daily power balance constraints and generation limits are considered. The microgrid system for this case study considered both of renewable energy plant and conventional generator units. There are two test systems that have been considered as case study. The first test system is a simple microgrid system which consists of three generators. The second test system consists of seven generating units including two wind turbines, three fuel-cell plants and two diesel generators. The IFA method has been implemented using MATLAB software. The results obtained by IFA was compared to FA and other algorithms based on optimal cost, convergence characteristics and robustness to validate the effectiveness of the IFA. It shows that the IFA obtained better results in terms of operating costs compared to FA, Differential Evolution (DE), Particle Swarm Optimization (PSO) and Cuckoo Search Algorithm (CSA)

    Study of power quality assessment for a photo-voltaic based Distribution Static Compensator (DSTATCOM)

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    This thesis presents an idea of PV cell or battery based dc to dc boost converter which is served to a voltage source converter (VSC) for enhancement of quality of power. A synchronous reference controller is suggested using distribution static compensator (DSTATCOM) in a 3-phase 4-wire transmission system. The DSTATCOM mainly comprises of one VSC and a dc-link capacitor. The main purpose of DSTATCOM is to provide source and total harmonic reduction, reactive power compensation and compensation of neutral current at point of common coupling .A PCC is a point on electricity network where consumer loads are connected. The boost converter used does the work of a chopper. It converts variable output dc to a fixed value of dc by stepping up of voltage equal to the DC-link necessity of voltage source converter. The main benefit of this planned scheme is that, it will always deliver continual compensation for the whole day. To provide separation to voltage source converter and path for fundamental of zero sequence components, one star/delta transformer is employed. It also helps to diminish neutral current by supplying a circulating route in secondary winding of transformer which is delta connected. The required gate pulse to IGBT’s and diode are provided from the PWM controller by using synchronous reference algorithm

    Towards the simulation of the whole manufacturing chain processes with FORGE®

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    International audienceFollowing the metal composition and the microstructure evolution during the whole manufacturing chain is becoming a key point in the metal forming industry to better understand the processes and reach the increasing quality requirements for the parts. Thus, providing a simulation tool able to model the whole chain becomes critical. Physical phenomena occurring during the processes are nowadays better understood, providing always more relevant models for numerical simulation. However, important numerical challenges still exist in order to be able to run those simulations with the required accuracy. This article shows how FORGE® tackles those issues in order to provide highly accurate microstructure and surface treatments simulation features applied on real industrial processes

    Study of ancient forging devices: 3D modelling and analysis using current computer methods

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    An ancient forging device in Spain has been studied, namely the forge with a waterwheel and air-blowing tube or hydraulic trompe, found near the village of Santa Eulalia de Oscos (province of Asturias, Spain). Three procedures using ad hoc methods were applied: 3D modelling, finite element analysis (FEA), and computational-fluid dynamics (CFD). The CFD results indicated the proper functioning of the trompe, which is a peculiar device based on the Venturi effect to take in air. The maximum air volume flow rate supplied to the forge by the trompe was shown to be 0.091 m3/s, and certain parameters of relevance in the trompe design presented optimal values, i.e. offering maximum air-flow supply. Furthermore, the distribution of stress over the motion-transmission system revealed that the stress was concentrated most intensely in the cogs of the transmission shaft (a kind of camshaft), registering values of up to 7.50 MPa, although this value remained below half of the maximum admissible work stress. Therefore, it was confirmed that the oak wood from which the motion system and the trompe were made functioned properly, as these systems never exceeded the maximum admissible working stress, demonstrating the effectiveness of the materials used in that period

    Design and study of SPD processes; HPT and MF

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    This master thesis aims to model the severe plastic deformation through the HPT (High Pressure Torsion) and MDF (Multi Directional Forging) methods in order to determine the necessary external loads. These external loads, see torque and pressure or exerted load, have been calculated through a finite element method and CAE software, and they will be used in a future project to develop a hydraulic torsion press in order to be able to develop the HPT SPD processes in the PROCOMAME (Procesos de Conformado de Materiales Metálicos) group laboratories in the EEBE (Escola d’Enginyeria de Barcelona Est) faculty of the Technical University of Catalonia (UPC). The results show the relation between the numbers of turns, torque, load and the effect of those over the material, illustrating the effective strain and stress accumulated along the process. The accumulated torque data is very promising, and shows a saturation in few turns, giving a reliable constant torque with which a hydraulic and torsion machine would be effectively designed, giving, of course, a safe margin of security. On the other hand, in cooperation with a research group from Autonomous National University of Mexico (UNAM), new state-of-the-art studies have been simulated in terms of a modified HPT processes. The process has the particularity that torsion and compression are applied at the same time, whereas normally pressure is first applied before torsion. The established relationship in México’s machine is 1 turn per 5 mm, and the main objective is to obtain the external loads and if the accumulated effective strain would be enough to process an ultra-fine grain material with the expected material properties. As a previous essay, a mechanical buckling effect is analytically performed beforehand in order to avoid this effect due to the small section as a function of sample length. The obtained results show a new possible method to obtain severe plastic deformation materials with a bigger size than other processes avoiding the plausible buckling effect, which is estimated around 40 and 70 mm for Aluminium 1100 depending on the set-up chosen. Finally, a thermal analysis simulation is performed for the MDF method in order to study the heat flux and its evolution generated along the process and after that, the heat flux dispersion evacuated out of the system. The results show a great concordance with empirical data obtained in a different master thesis developed in parallel inside the same department, reaching to temperatures of 1ºC in the external face of the dies

    Effect of the tool tilt angle on the heat generation and the material flow in friction stir welding

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    This work studies the effect of the tool tilt angle on the generated heat and the material flow in the work pieces joint by Friction Stir Welding (FSW). An apropos kinematic framework together with a two-stage speed-up strategy is adopted to simulate the FSW problem. The effect of tilt angle on the FSWelds is modeled through the contact condition by modifying an enhanced friction model. A rotated friction shear stress is proposed, the angle of rotation depending on the process parameters and the tilt angle. The proposed rotation angle is calibrated by the experimental data provided for a tilt angle 2.5°. The differences of generated heat and material flow for the cases of tool with tilt angle of 0° and 2.5° are discussed. It is concluded that due to the higher temperature, softer material and greater frictional force in the trailing side of the tool, the material flow in the rear side of the FSW tool with the title angle is considerably enhanced, which assists to prevent the generation of defect.Peer ReviewedPostprint (published version

    Evaluation of lubricants for cold forming of steels by double-cup extrusion tests

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    The double-cup extrusion testing method was chosen for measuring the pressure and material flow parameters in order to quantify the frictional shear factor between the workpiece and the forming tool in cold metal forming processes. The test was adapted to be used under production conditions and applied to characterize and compare the lubrication properties of different types of lubricants and coatings.;It was found to be a useful approach to estimate the relative efficiency of different lubricants and coating methods. It indicated that one specific lubricant has significantly superior lubricant characteristics than others.;FEA analysis of the experimental setup was constructed to generate calibration curves for the coefficient of friction, m, at various values of m and deformation stroke by using the metal forming software package ANTARES. Statistical techniques were utilized to calculate the mean and variance of results obtained for various combinations of the experimental control variables.;Additional efforts are needed in order to make the test results more sensitive to slight variations of friction within a given lubrication method

    Study of Abnormal Grain Growth in Beta Annealed Ti-6al-4v Forgings

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    Beta annealed Ti-6Al-4V has been used extensively in current aerospace platforms due to properties such as high strength to weight ratio. Recent inspections during aircraft production have revealed regions of excessive grain sizes, resulting in quarantined parts and excessive time spent on root cause analysis and risk mitigation efforts. Uncertainty surrounding these parts has led to increased costs and may cause future aircraft production delays. Part manufacturers have intermittently reported problems with abnormal grain growth in these alloys for years, but to date no supplier has been able to determine the source of this microstructural phenomenon. Leveraging common Finite Element Method (FEM) software, sidepressing and upsetting forging processes are simulated to predict internal strain and temperature results for use in identifying regions of localizations effecting grain development. Results were used to guide forging tests in an attempt to reproduce abnormal grain growth in the material. Microscopy and image analysis were used to quantify effects of forging parameters on successful development of coarse grains in sidepressing and upsetting forgings. This work seeks to directly support Air Force Research Laboratory (AFRL)’s Materials and Manufacturing Directorate in determining cause of this ongoing issue
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