Department of Mechanical Engineering

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https://escholar.umt.edu.pk/handle/123456789/1178

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Browsing Department of Mechanical Engineering by Author "Asad, Muhammad"

Now showing 1 - 4 of 4
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    Modeling of Aerodynamic Forces on the Wind Turbine Blades
    (Journal of Clean Energy Technologies, 2015) Asif Memon; Saleem R. Samo; Asad, Muhammad; Fareed H. Mangi
    This research work is aimed to improve the wind turbine modeling for a better representation of aerodynamic forces around the blades. The modeling of forces has been carried out using the actuator surface hybrid model. This model combines the blade element method and Navier-Stokes equation solver. The forces are extracted using real airfoil section of S809 in order to impose on the line which represents the actuator surface. The near wake is calculated and compared with the proposed model and the existing models.
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    A numerical approach on parametric sensitivity analysis for an aeronautic aluminium alloy turning process
    (Mechanica, 2016-03-15) Asad, Muhammad
    The understanding of physical parameters of machining processes of aerospace grade aluminium alloy is always of prime importance. The main concern is always to understand the chip formation process and the resultant cutting force experienced by the tool due to different parameters like cutting speeds, feed rate, friction coefficient and tool rake angle etc. The finite element analysis has replaced many expensive and time consuming physical machining processes. In the present work, an extensive study of different parameters affecting the turning process of aluminium alloy (A2024-T351) is performed using finite element analysis. The Johnson-Cook ductile material model based on coupled plasticity and damage evolution is employed to simulate the cutting process. The authenticity of the performed simulation work is verified by comparing the simulation results with available experimental data on machining of aluminium alloy (A2024-T351).
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    A parametric sensitivity study on preforming simulations of woven composites using a hypoelastic computational model
    (Journal of Reinforced Plastics and Composites, SAGE, 2016-02-01) Asad, Muhammad
    Preforming simulation for structural composite processing can significantly assist in the development of forming tools, prediction of manufacturing issues, optimization of process parameters and structural design analysis. The present study is aimed at investigating the influence of some important parameters in composite forming using a hypoelastic computational model developed for simulating the deformation behaviour of fibrous materials. The process parameters considered within this numerical work investigate the effects of binder force, coefficient of friction and forming speed. The study is conducted using two most commonly used double-curvature geometries for analysis of woven composites: double dome and hemisphere. It has been shown with this comprehensive study that the forming simulations are greatly affected by the choice of process parameters, and models based on finite element approach, such as the proposed hypoelastic model, can only predict its effects.
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    Some insight on the modeling of chip information and its morphology during metal cutting operations.
    (Comptes Rendus Mecanique, Elsevier, 2015-08-22) Asad, Muhammad
    The present paper deals with the mechanisms of chip formation during cutting operations. It deals with some experiments characterising the chip morphologies and microstructure chip investigations under high loadings. In this contribution, mechanisms of chip segmentation are presented. The effect of cutting conditions on cutting forces is treated. Consequently, the chip segmentation phenomenon was correlated to cutting forces evolutions. Also, an investigation on chip strain localisation is carried out. Numerical simulations dealing with chip formation and considering thermomechanical phenomena are also presented. Some numerical results related to chip formation based on the theory of strain gradient plasticity are also discussed. Moreover, the effect of machining system stiffness on chip segmentation is analysed.