The Experts below are selected from a list of 15747 Experts worldwide ranked by ideXlab platform
Burak Deger - One of the best experts on this subject based on the ideXlab platform.
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mechanistic force modeling for milling of unidirectional carbon fiber reinforced polymer laminates
International Journal of Machine Tools & Manufacture, 2012Co-Authors: Yigit Karpat, Onur Bahtiyar, Burak DegerAbstract:Abstract Carbon fiber reinforced polymer (CFRP) usage in the aerospace industry has been steadily increasing due to its superior material properties such as high strength, low weight, high resistance to corrosion, and a low thermal expansion coefficient. In addition, CFRP parts are produced near-net-shape, a process that eliminates rough machining operations. However, machining operations such as drilling, side milling, and slotting are still necessary to give the CFRP parts their final shape. A majority of the studies on machining of CFRP laminates are on drilling. The number of studies on milling of CFRPs is quite limited. In this study, a mechanistic Cutting force model for milling CFRPs is proposed based on experimentally collected Cutting force data during slot milling of unidirectional CFRP laminates using two different polycrystalline diamond cutters. Cutting force coefficients in radial and tangential directions are calculated as a function of fiber Cutting Angle. The relationship is represented with simple sine functions. The mechanistic model is shown to be capable of predicting Cutting forces during milling of multidirectional CFRP laminates. The experimental milling force measurements and predicted milling forces agree well with each other. Surface milling experiments were also conducted to investigate the relationship between milling forces and surface quality. Some suggestions on surface milling of CFRP laminates are given based on these observations.
W Arnold - One of the best experts on this subject based on the ideXlab platform.
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finite element simulation of moldboard soil interaction
Soil & Tillage Research, 2013Co-Authors: Hatem Bentaher, Ayadi Ibrahmi, Elyes Hamza, M Hbaieb, G Kantchev, Aref Maalej, W ArnoldAbstract:Abstract The efficiency of the tillage is measured by the power consumption or the tillage force or draught and the quality of the worked soil. The tillage forces are mainly a function of soil mechanical properties, working parameters of the tool (e.g. depth and speed) and tool geometry. In this paper we report on the numerical modeling of soil tillage. The finite element method (FEM) was used to model the Cutting process of the soil using a moldboard. The surface geometry of the moldboard was measured with a 3D touch probe bench, also called coordinate measuring machine, and these data were used to construct the shape with SolidWorks design software. An elasto-plastic constitutive model was used for the soil. The generated surface of the plow was imported to Abaqus software as a discrete rigid body with a reference point at the tip of the moldboard. At this tip the reaction force with its three orthogonal components was calculated. The impact of the Cutting Angle (Angle between the horizontal generatrix and the tillage direction) and the lift Angle (Angle between the moldboard surface and the horizontal line in an orthogonal section to the Cutting edge) on draught force was investigated. The optimal values of these Angles are in agreement with experimental data from the literature.
Yigit Karpat - One of the best experts on this subject based on the ideXlab platform.
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mechanistic force modeling for milling of unidirectional carbon fiber reinforced polymer laminates
International Journal of Machine Tools & Manufacture, 2012Co-Authors: Yigit Karpat, Onur Bahtiyar, Burak DegerAbstract:Abstract Carbon fiber reinforced polymer (CFRP) usage in the aerospace industry has been steadily increasing due to its superior material properties such as high strength, low weight, high resistance to corrosion, and a low thermal expansion coefficient. In addition, CFRP parts are produced near-net-shape, a process that eliminates rough machining operations. However, machining operations such as drilling, side milling, and slotting are still necessary to give the CFRP parts their final shape. A majority of the studies on machining of CFRP laminates are on drilling. The number of studies on milling of CFRPs is quite limited. In this study, a mechanistic Cutting force model for milling CFRPs is proposed based on experimentally collected Cutting force data during slot milling of unidirectional CFRP laminates using two different polycrystalline diamond cutters. Cutting force coefficients in radial and tangential directions are calculated as a function of fiber Cutting Angle. The relationship is represented with simple sine functions. The mechanistic model is shown to be capable of predicting Cutting forces during milling of multidirectional CFRP laminates. The experimental milling force measurements and predicted milling forces agree well with each other. Surface milling experiments were also conducted to investigate the relationship between milling forces and surface quality. Some suggestions on surface milling of CFRP laminates are given based on these observations.
Hatem Bentaher - One of the best experts on this subject based on the ideXlab platform.
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study the effect of tool geometry and operational conditions on mouldboard plough forces and energy requirement
Computers and Electronics in Agriculture, 2015Co-Authors: Ayadi Ibrahmi, Hatem Bentaher, M Hbaieb, Aref Maalej, Abdul Mounem MouazenAbstract:Experimental validation of FEM results in part 1 using soil bin.The effect of the depth and the speed on tillage forces.The influence of the Cutting Angle (α) and the lifting Angle (β) on tillage forces.The influence of the Cutting Angles (α and β) on the soil loosening and inversion.The influence of the depth and speed on the soil loosening and inversion. Forces acting on tillage tools directly affect vehicle fuel consumption of tillage operations. Both tool forces and soil disturbance are a function of tillage tool type, tool geometry, and operational conditions. A soil bin experiment in a sandy loam soil was conducted to validate the results obtained from the finite element method (FEM) simulation of the interaction between soil and a mouldboard plough, carried out in part 1 of this study. An octagonal load cell was used to measure the draught and vertical forces. A special support was manufactured to modify the Cutting Angle (alpha) and the lifting Angle (beta). Tillage forces and soil disturbance were measured for different speed (0.5, 1, 1.5, and 2m/s), depth (100, 150, 200, and 250mm), Cutting (30?, 45?, 60?, and 75?), and lifting (25?, 40?, and 55?) Angles, and were presented for the same soil conditions of those considered in the FEM. The soil disturbance including the width and surface area of the cut soil, and the height, width, and the surface area of the soil inversion were measured with a laser scanner. Results showed that both the FEM calculations and the soil bin measurement presented the same tendency for the variation of draught and vertical forces with speed, depth, Cutting, and lifting Angles. The maximum error recorded between the measured and the FEM results was 33.8%. It was found that the draught and vertical forces increased linearly with speed, whereas a second order polynomial and linear relationships were established with depth, respectively. Draught increased linearly with both the Cutting and lifting Angles, whereas, the vertical force decreased linearly with these Angles. The study of the soil disturbance showed that the operating conditions (speed, depth, and Cutting Angles) of the mouldboard plough had an important effect on the quality of the tillage (soil loosening and inversion). Both the FEM and the soil bin tests showed that at a working speed of 1m/s and a depth of 150mm with lower lifting and Cutting Angles of 25? and 45?, respectively, provide the best combination for lowering energy consumption. The soil bin tests showed that these settings provide a good soil disturbance.
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study the effect of tool geometry and operational conditions on mouldboard plough forces and energy requirement part 1 finite element simulation
Computers and Electronics in Agriculture, 2015Co-Authors: Ayadi Ibrahmi, Hatem Bentaher, M Hbaieb, Aref Maalej, Abdul Mounem MouazenAbstract:Abstract The finite element method (FEM) is commonly used to study the soil Cutting process with tillage tools. This paper illustrates the use of FEM to model interaction of a mouldboard plough used in northern Africa. A Drucker–Prager elasto-plastic model was used to simulate the material behavior of a sandy loam soil. The mouldboard was considered as a discrete rigid body with a reference point at the tip, at which the three orthogonal force components (vertical, lateral, and draught) were calculated. The effects of the mouldboard depth of cut, speed of operation, Cutting Angle ( α ) and the lifting Angle ( β ) on the tillage forces were investigated in this study. Results showed that draught force increased with a second order polynomial function with depth, whereas the vertical and lateral forces had a linear relationships with depth. Moreover, these forces increased linearly with speed. For the effect of the Cutting Angles, results showed that the draught force increased linearly with the Cutting and the lifting Angles. The vertical force decreased linearly with these Angles. Whereas, the lateral force decreased with a polynomial trend with the Cutting Angle and increased linearly with the lifting Angle. It was found that the minimal energy consumption can be achieved by a combination of a working depth of 150 mm, a speed of 1 m/s, low lifting Angle (25°), and Cutting Angle (from 30° to 45°). This combination also resulted in a good soil inversion. It can be concluded that FEM can be used to understand the effect of mouldboard design and operational conditions on tillage forces, energy requirements, and quality of soil inversion.
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finite element simulation of moldboard soil interaction
Soil & Tillage Research, 2013Co-Authors: Hatem Bentaher, Ayadi Ibrahmi, Elyes Hamza, M Hbaieb, G Kantchev, Aref Maalej, W ArnoldAbstract:Abstract The efficiency of the tillage is measured by the power consumption or the tillage force or draught and the quality of the worked soil. The tillage forces are mainly a function of soil mechanical properties, working parameters of the tool (e.g. depth and speed) and tool geometry. In this paper we report on the numerical modeling of soil tillage. The finite element method (FEM) was used to model the Cutting process of the soil using a moldboard. The surface geometry of the moldboard was measured with a 3D touch probe bench, also called coordinate measuring machine, and these data were used to construct the shape with SolidWorks design software. An elasto-plastic constitutive model was used for the soil. The generated surface of the plow was imported to Abaqus software as a discrete rigid body with a reference point at the tip of the moldboard. At this tip the reaction force with its three orthogonal components was calculated. The impact of the Cutting Angle (Angle between the horizontal generatrix and the tillage direction) and the lift Angle (Angle between the moldboard surface and the horizontal line in an orthogonal section to the Cutting edge) on draught force was investigated. The optimal values of these Angles are in agreement with experimental data from the literature.
Dragos Axinte - One of the best experts on this subject based on the ideXlab platform.
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modelling the unidirectional fibre composite milling force oscillations through capturing the influence of the stochastic fibre distributions
Composite Structures, 2019Co-Authors: Oriol Gavalda Diaz, Dragos AxinteAbstract:Abstract Although high frequency variation of Cutting forces is an inherent characteristic when milling composites, studies and models on the explanation and time-domain simulation of such processing forces seem to be missing in the literature. This paper first claims that the variation of the composite milling forces comes from three aspects: i) the variation of chip thickness caused by the cycloid trajectories of the Cutting edge; ii) the random fibre placements within the composite and iii) the continuous variation of the Cutting direction relative to the fibre orientation due to the rotational motion of the milling cutter. Moreover, the cutter’s helix Angle leads to each section of the Cutting edge engaging different fibre orientations simultaneously, adding additional challenges in understanding and predicting the resultant forces. Thus, this paper develops an analytical approach which can be utilised to accurately simulate the milling forces in time domain for unidirectional fibre composites. The approach calculates the chip thickness, estimates the stochastic fibre placements and defines variable Cutting coefficients for different fibre orientations to integrate their effects on the force variability. Besides, the helical cutter is discretized into several slices to simulate the force acting on each engaged part at its relevant fibre Cutting Angle, resulting in a procedure of simulating the composite Cutting force with helical milling cutter. Both straight and helical milling cutters are taken into account to validate the model, the effects from the concluded three aspects are separately investigated to provide an in-depth understanding of the force variation and support the developed model. It is observed that the variation of milling forces follows a Gaussian distribution when the Cutting direction of the fibre is fixed. Furthermore, the simulated milling forces show a satisfactory agreement with the experimental results, especially their oscillations illustrate a high degree of consistency.
