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Analysis and Prediction of Crack Propagation in Plates by the Enriched Free Galerkin Method
Bui Manh Tuan,
Chen Yun Fei
Issue:
Volume 2, Issue 6, December 2014
Pages:
78-86
Received:
6 November 2014
Accepted:
21 November 2014
Published:
25 November 2014
Abstract: This paper presents a centre and edge crack analysis using meshless methods which is based on moving least squares (MLS) approximation. The unknown displacement function u(x) is approximated by moving least square approximation uh(x). These approximation are constructed by using a weight function which is based a monomial basis function and a set of non-constant coefficients. A subdivision that is similar to finite element method is used to provide a background mesh for numerical integration. An enriched EFG formulation with fracture problems is proposed to improve the solution accuracy for linear elastic fracture problem. The essential boundary conditions are enforced by Lagrange multipliers method. A code has been written in Matlab for the analysis of a crack tip. The obtained results of the developed EFG-code were compared to available experimental data and other numerical (exact methods and finite element method) methods.
Abstract: This paper presents a centre and edge crack analysis using meshless methods which is based on moving least squares (MLS) approximation. The unknown displacement function u(x) is approximated by moving least square approximation uh(x). These approximation are constructed by using a weight function which is based a monomial basis function and a set o...
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The Elastic Scattering of an Electron from the Target BY Absorbing a Photon via Free- Free Scattering Theory
Kishori Yadav,
Jeevan Jyoti Nakarmi
Issue:
Volume 2, Issue 6, December 2014
Pages:
87-97
Received:
7 November 2014
Accepted:
18 November 2014
Published:
28 November 2014
Abstract: This paper intended to the elastic scattering of an electron from the target by absorbing a photon from the laser field has been studied for the polarized potential. Since the solution of the Schro ̈dinger equation of whole three-body system has not been found, we consider such intensities of electromagnetic field (Laser field) that the electron field coupling is the dominant process and the target is transparent to the field such that photon- target coupling can be ignored. Therefore the internal structure of target can be ignored and represented just as a scattering potential. For number of photon, l=-1 i.e, absorption of a photon (inverse Bremsstrahlung), we have concluded that the differential scattering cross section of an electron depends upon the fourth power of the wavelength (λ^4) and the intensity of the Laser field. From this work we see that at certain values of laser parameters the differential scattering cross section of scattered electron decreases with increase in scattering angle and attains a minimum value of 0.1 barn and further increase in scattering angle also increases in differential scattering cross section and attains a maximum value of 0.3 barn.
Abstract: This paper intended to the elastic scattering of an electron from the target by absorbing a photon from the laser field has been studied for the polarized potential. Since the solution of the Schro ̈dinger equation of whole three-body system has not been found, we consider such intensities of electromagnetic field (Laser field) that the electron fi...
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Experimental Study on Thermal Conductivity of Teak Wood Dust Reinforced Epoxy Composite Using Lee’s Apparatus Method
Ramesh Chandra Mohapatra,
Antaryami Mishra,
Bibhuti Bhushan Choudhury
Issue:
Volume 2, Issue 6, December 2014
Pages:
98-103
Received:
23 November 2014
Accepted:
9 December 2014
Published:
18 December 2014
Abstract: In the present work, the effective thermal conductivity of teak wood dust (TWD) filled epoxy composites at different volume fractions (6.5, 11.3, 26.8 and 35.9%) have been determined experimentally by using Lee’s Apparatus. Composites of teak wood dust particles of 150µ, 200µ and 250µ sizes with varying volume fractions (6.5, 11.3, 26.8 and 35.9%) have been developed by hand lay up technique. From the tests it is observed that for each size of TWD, the thermal conductivity values of composites decreases with increase of filler content which indicates that the TWD reinforced epoxy composites have good insulation properties. It has also been found that the composite with 150µ particle size of teak wood dust at same volume fractions exhibited lowest thermal conductivity compared to composites with 200µ and 250µ of teak wood dust. Therefore the composite with particle size 150µ at 35.9% volume fraction teak wood dust may be more suitable for insulation applications. Experimental results (TWD,150µ) are also compared with the theoretical models (such as Rule of Mixture model, Russel model, Maxwell model Baschirow & Selenew model ) and found that the errors associated with all the above four models with respect to experimental ones lie in the range of 20.14 to 84%, 74 to111.84%, 79.13 to 115.79% and 60.13 to 102% respectively.
Abstract: In the present work, the effective thermal conductivity of teak wood dust (TWD) filled epoxy composites at different volume fractions (6.5, 11.3, 26.8 and 35.9%) have been determined experimentally by using Lee’s Apparatus. Composites of teak wood dust particles of 150µ, 200µ and 250µ sizes with varying volume fractions (6.5, 11.3, 26.8 and 35.9%) ...
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On Some Problems of Synthesis of Spatial Five-Bar Hinged Mechanisms with Two Degrees of Freedom
Nodar Davitashvili,
Otar Gelashvili
Issue:
Volume 2, Issue 6, December 2014
Pages:
104-110
Received:
24 November 2014
Accepted:
7 December 2014
Published:
18 December 2014
Abstract: Solution of the problems of synthesis of spatial five-bar hinged mechanisms with two degrees of freedom task considering the angle of transmission and definition of conditions of existence of cranks is given in the paper. A possibility of movement of the designed mechanism without seizure that is depended on shape and sizes of the mechanism links is envisaged. At solution of the problem of synthesis first are determined sizes of the mechanism couples considering the angle of transmission and then are determined the limits of variation of the angle of transmission depending on sizes of the mechanism links. The conditions are ascertained which must be met by sizes of the spatial five-bar mechanism links so that the two links adjoining to the frame are crank (theorem on existence of cranks in the spatial five-bar mechanism).
Abstract: Solution of the problems of synthesis of spatial five-bar hinged mechanisms with two degrees of freedom task considering the angle of transmission and definition of conditions of existence of cranks is given in the paper. A possibility of movement of the designed mechanism without seizure that is depended on shape and sizes of the mechanism links i...
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Characterization of Amorphous Ribbon by Means Vibrating Sample Magnetometry as an Interesting Tool to Investigate a Possible Detector of Vector Field
Arturo Mendoza Castrejón,
Herlinda Montiel Sánchez,
Guillermo Alvarez Lucio,
Damasio Morales Cruz
Issue:
Volume 2, Issue 6, December 2014
Pages:
111-116
Received:
30 November 2014
Accepted:
16 December 2014
Published:
22 December 2014
Abstract: Characterization of amorphous ribbon is made by using Vibrating Sample Magnetometry VSM technique with different geometric arrangements: P10, P190, P20 and P290. The purpose is to determine the evolution of the saturation magnetization MS, retentivity MR and magnetic anisotropy K1 as a function of annealing time treatment and also as a function of the geometric arrangement. The rate of change of magnetization ∆M/∆H is determined for orientation P190 and orientation P290. These values of rate of change for the ribbon with no annealing treatment are: 0.122 emu/cm3 and 0.11 emu/cm3, respectively. The highest values of anisotropy are for orientation P190 and for orientation P290, these values are: K1 = 2,365,100 erg/cm3 and K1 = 2,405,520 erg/cm3, respectively. Thus we establish that the amorphous ribbon is a strong candidate for technological applications in the area of the magnetic industry, because they can be designed vector field detectors in three directions: longitudinal, transverse (to the ribbon axis) and normal to ribbon plane.
Abstract: Characterization of amorphous ribbon is made by using Vibrating Sample Magnetometry VSM technique with different geometric arrangements: P10, P190, P20 and P290. The purpose is to determine the evolution of the saturation magnetization MS, retentivity MR and magnetic anisotropy K1 as a function of annealing time treatment and also as a function of ...
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Simulation and Experimental of Oil-Water Flow with Effect of Heat Transfer in Horizontal Pipe
Esam Mejbel Abed,
Zahra'a Aamir Auda
Issue:
Volume 2, Issue 6, December 2014
Pages:
117-127
Received:
26 November 2014
Accepted:
18 December 2014
Published:
27 December 2014
Abstract: There is a strong tendency for two immiscible fluids to arrange themselves so that the low viscosity constituent is in the region of high share. Therefore, it may be possible to introduce a beneficial effect in any flow of a very viscous liquid by introducing amount of a fluid lubricated as liquid-liquid oil-water flow. Two main classes of flows are seen, annular and small bubble in all experimental results. The pressure drop and mean heat-transfer coefficients were observed to depend strongly on the flow patterns. A correlation of the two-phase mean heat-transfer coefficients, based on a simple model of liquid flow, with a Reynolds number based on the actual mean velocity of the liquid mixture two-phase flow, were developed. An experimental rig facility has been designed and constructed, to enable measurements of local parameters in oil-water flow in the developing region of the flow in a 32 mm ID 6 m long pipe. The large discrepancies between model predictions and experimental data are reported in the literature review that the physics of oil-water flow is complex and not yet fully understood. The flow patterns that appear are classified in flow pattern maps as functions of either mixture velocity and water cut or superficial velocities. From these experiments a smaller number of annular flows are selected for studies of velocity and turbulence. The theoretical study was executed using software Fluent program, a modified turbulent diffusion model is presented. Simulation results carried out with the model show more physical predictions with respect to the particle deposition process and concentration profile. The theoretical results represent the pressure gradient distribution, velocity and mean heat transfer coefficient, pressure contours, velocity vectors, streamlines, and also velocity profiles. It was found that the methods with more restrictions (in terms of the applicable range of void fraction, liquid superficial Reynolds number) give better predictions.
Abstract: There is a strong tendency for two immiscible fluids to arrange themselves so that the low viscosity constituent is in the region of high share. Therefore, it may be possible to introduce a beneficial effect in any flow of a very viscous liquid by introducing amount of a fluid lubricated as liquid-liquid oil-water flow. Two main classes of flows ar...
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Effect of Welding Parameters on Weld Bead Shape for Welds Done Underwater
Joshua Emuejevoke Omajene,
Jukka Martikainen,
Paul Kah
Issue:
Volume 2, Issue 6, December 2014
Pages:
128-134
Received:
18 November 2014
Accepted:
30 November 2014
Published:
4 January 2015
Abstract: The desire to model a control system so as to optimize the welding process parameters and the effect of the environment during underwater wet welding makes it necessary to study the effects of these parameters as it affects the weld bead geometry of welds achieved in underwater welding. The objective of this paper is to analyze how welding arc current, voltage, speed, and the effect of the water environment affect the weld bead geometry such as bead width, penetration, and reinforcement height. Comparing the differences of the effects of welding input parameters for air and wet welding as it affects the welding output quality parameter is the method employed in this research paper. The result of this study will give a better understanding of applying control mechanism in predicting the quality of a weld during underwater welding. A clearer insight of the weldability of structural steels for offshore applications as it relates to underwater welding, having a full knowledge of the nonlinear multivariable parameters is indicative of better control methods.
Abstract: The desire to model a control system so as to optimize the welding process parameters and the effect of the environment during underwater wet welding makes it necessary to study the effects of these parameters as it affects the weld bead geometry of welds achieved in underwater welding. The objective of this paper is to analyze how welding arc curr...
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