Table of content

Iraqi journal of mechanical and material engineering

المجلة العراقية للهندسة الميكانيكية وهندسة المواد

ISSN: 20761819
Publisher: Babylon University
Faculty: Engineering
Language: Arabic and English

This journal is Open Access

About

Iraqi journal for mechanical and material engineering is a refereed scientific journal published quarterly by the engineering college/ university of Babylon. It deals with high quality researches in fields of mechanical and material engineering.

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Contact info

Journal E-mail:
j.mec_mat_eng@yahoo.com
Babylon university/Babylon/Iraq P.O.Box(4)
Tel:++96430245387.(1155)

Table of content: 2011 volume:11 issue:1

Article
EFFECT OF DIE SHAPE ON THE TEMPERATURE AND STRESSES DISTRIBUTION IN THE COMPOUND (FORWARD-BACKWARD) EXTRUSION PROCESS
تأثير الشكل الهندسي للقالب على توزيع درجات الحرارة والاجهادات المكافئة في عملية البثق المركب (الخلفي – الامامي)

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Abstract

ABSTRACT In this research the effect of the die geometry in the compound extrusion (forward – backward) process on the distribution of temperature and effective stresses is investigated; Effect of the geometrical shape of extrusion process on the power required for the forming process was also investigated. The flat surface for the punch is chosen and two types of die shape (flat and arc) are studied. The analysis of temperature and stresses distribution in the die and billet is studied using finite element method via ANSYS software. The contact region was taken into consideration. From the results, it was noted that there a tiny changes in the pattern of temperature distribution and also a huge changes in the equivalent stress levels due to the changing in die geometry. In the backward extrusion process, a significant effect on the stress levels was also noticed due to changing in die geometry. At last, the results show that the best results of was achieved at arc die geometry .


Article
COMPUTER AIDED SPUR GEAR DATA EXTRACTION BASED ON IMAGE PROCESSING TECHNIQUE
إستخلاص بيانات التروس العدلة المعان بالحاسوب بالأعتماد على تقنية معالجة الصورة

Authors: Ali Abbar Khleif
Pages: 13-21
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Abstract

ABSTRACT This paper proposed a computerized methodology of spur gears reconstruction and feature extraction using image processing technique. The methodology was prepared, by building a suitable logical program in Matlab environment, to process the captured gear image using mathematical and logical relationships for the purpose of spur gear data extraction required for 3D spur gear modeling which is include No. of teeth, tooth height, Pitch circle, … etc. The proposed system has been tested on different spur gears, and the extracted data shows reliable spur gear modeling, which generates accurate and efficient model and provides substantial saving in time and cost of production.


Article
Numerical Study of Laminar Fluid Flow and Heat Transfer in the Entrance Region of a Circular Pipe
دراسة عددية لجريان الموائع الطباقي وانتقال الحرارة في مدخل الانبوب الدائري

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Abstract

Abstract : This research represents a theoretical study which deals with the developing steady, laminar, Newtonian and incompressible fluid flow and heat transfer through circular tube .The effects of heat conduction, body force, free convection, heat generation and viscous dissipation within the fluid are neglected. A computer program was built by using Gaussian elimination method to perform the numerical marching technique solution with finite difference method for two case of heating ,constant wall temperature and constant wall heat flux boundary conditions for different values of Reynolds number(500,1000,2000)and Prandtl number(1, 2.5, 5). This approach provides a picture of the variation of the velocity and temperature profiles through the tube. The computational algorithm is able to calculate all the hydrodynamic properties such as velocities and pressure drop . Also it is able to predict all the thermal properties such as the temperature, bulk temperature, and local Nusselt number. The velocity profile becomes fully developed at approximately Re05.02aLe, and the temperature distribution becomes fully developed at approximately Pr.Re05.02aLet, as expected


Article
REDUCTION OF STRESS INTENSITY FACTOR IN A UNIAXLALLY LOADED CRACKED PLATE
تقليل معامل تمركز الاجهادات في الصفيحة الحاوية على شق والمحملة باتجاه واحد

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Abstract

Abstract. This paper presents work in progress, concerning the reducing of stress intensity factor values for finite width plates by using auxiliary circular holes, the analysis is done by using the finite element method. To find the stress intensity factor “SIF”, the ANSYS packages was implemented to evaluate the SIF by using th Finite Element of Fracture Mechanic. It had found out that the SIF is reduced to 56% by using the auxiliary hole in the plate, the dynamic load of unit step input had been test to show the validity of this method, which is better to prevent crack from propagation.


Article
THE DEPENDENCE OF PITTING CORROSION MORPHOLOGY ON THE PRECIPITATED PHASES FOR 7020 AL-ALLOY
اعتمادية التكوين التشكيلي ( مورفولوجيا) للتاكل النقري على الاطوار المترسبة 7020 في سبيكة المنيوم نوع

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Abstract

Abstract Al-alloy type 7020 was heated at different temperature (from 100 to 500) ºc to observed the shape of precipitated phases. Pitting corrosion of this alloy was also study by using immersion in 3.5% NaCl and polarization techniques. The aim of this paper is to find the dependence of pitting corrosion morphology on the precipitated phases for 7020 Al-alloy. The results are confirmed that, at low heating temperatures between (100-200) °C dendrite structures were observed. These zones suffered dendrite pitting corrosion, when the alloy was exposed to corrosive medium of 3.5% NaCl. At the intermediate temperatures range (250-350) °C, different shapes precipitated phases are obtained. As heating temperature was increased these shapes converted from dendrite to spherical shapes. This transition in shapes was also observed for developed pit. At heating temperature up to 500 °C most of the formed pitting has the spherical overall shapes corresponded with the phases shape, precipitated at these range of temperatures.


Article
STUDYING OF FLAPS AND SLATS EFFECTS ON IMPROVING THE AERODYNAMIC FORCES OF THE WINGS
دراسة تأثير الشرائح واللوحات على تحسين قوى الديناميكية الھوائية للأجنحة

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Abstract

ABSTRACT: A numerical method was used for calculation the pressure distribution and then finding aerodynamic forces to give an estimation for the high- lift systems effect on two-dimensional airfoil for an inviscid incompressible flow (panel method), the computational method investigated experimentally. The study focused on flap and slat effects on the aerodynamic forces at the wings as two of the important items of the high lift systems. Experimental study was made with suction type low-speed wind tunnel for an airfoil of (NACA 0015) supported with leading edge slat and trailing edge flap. The effective forces of lift and drag were measured by two components balance. Different angles of attack (-4, 0, 4, 8 & 12)o and different flap angles (0, 10, 20 & 30)o were chosen with and without slat, variable air velocities (8, 12, 16 & 20)m/s were applied. The computational results compared with experimentally measured data.

Keywords

(Flap --- High-Lift --- Airplane --- wings --- panel method)


Article
VISCOELASTIC AND VISCOPLASTIC ANALYSIS OF POLYETHYLENE PIPE UNDER PRESSURE LOADING USING SPACE-TIME FINITE ELEMENT METHOD
التحليل اللزج المرن واللزج اللدن لانابيب البولي اثلينتحت حمل الضغطباستخدام طريقة العناصر المحددة

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Abstract In this paper, the viscoelastic and viscoplastic behavior of polyethylene (PE) pipe is studied and analyzed using Space-time finite element method (FEM). The (FEM) is achieved for Maxwell model and then the program is developed in three dimensions (two-dimension in space and one dimension in time) and applied to (PE) pipe under pressure loading. The time dependent partial differential equations describing the viscoelastic deformation of (PE) pipe under pressure loading for Maxwell element is solved using variational Galerkin continuous method in an integral process using time slabs. As a result of this study, the FEM in viscoelastic Maxwell model used to predict the relaxation modulus give accurate result compared to analytical which used Prony series. The stress increases to large values at the first stage of applied pressure loading and then decrease with increasing time. The viscoplastic surface density of micro crack is increasing function with increasing plastic strain.


Article
IMPROVEMENT OF CUTTING CONDITIONS USING OXY – PROPANE FLAME THROUGH CNC CUTTING MACHINE
تحسين حالة القطع باستخدام شعلة البروبان باستخدام ماكنة القطع المبرمجة

Authors: Talib H.Rashid طالب رشيد
Pages: 92-103
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Abstract

ABSTRACT In this research a flame of CNC cutting machine was used. It works manually only in straight line cut. All experiments had been done to reach a proper ultimate processing conditions for clean cut. The dwell time of preheating, piercing and the speed of cutting are variables - in addition to gas pressure - control the cutting process. The target was to improve cutting conditions of carbon steel metal of thickness arranged from (10–15) mm, then to design a written program to be fed with the final readings to the CNC machine to produce a complex frame having sections of straight lines, curves and right angles with tolerance of 0.1mm. The value of cut width which was (2) mm would be shifted toward the core dimensions according to the program. By this technique, it is capable to produce complex shapes such as gears, in particular big components having a clean and even cut for applications require less accuracy.

Keywords

cutting --- CNC machine --- propan flame


Article
EFFECT OF BLADE STAGGER ANGLE ON THE VIBRATION CHARACTERISTICS OF AXIAL FAN IN TURBOMACHINARY SYSTEM BY FINITE ELEMENT METHOD USING ANSYS
تأثير زاويةِ تمايلِ النصلِ على خصائصِ إهتزازَ المروحةِ المحوريِة في انظمةِ الماكنة النفاثة بطريقةِ العناصرِ المحددةِ باستخدام برنامج الأنسز

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Abstract

ABSTRACT This paper discusses the dynamic behavior (natural frequencies, modes shapes) of the axial fan. The fan blade stagger angle are adjustable. Three angles 20o, 35o and 60o are studied. Three dimensional finite elements with six degrees of freedom per node are employed to idealize the axial fan. ANSYS12 program is performed that takes the variables of the fan blade system. The obtained results reported the tenth structural natural frequencies and mode shapes which are based upon the behavior of fan, it can be shown that the natural frequency of the fan increased with increasing mode number and the amplitude decreases as the stagger angle increases. The results shows that the maximum amplitude occurred at stagger angle of 20° and have less error ratio.

Keywords

pumps --- vibration --- finite element


Article
Studying the effect of Fins length of Heatsink on the Performance of the Processor Type Athlon
]دراسة تاثير طول الزعنفة لمبدد حراري على اداء المعالج نوع اثلون

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Abstract

Abstract: In this paper we studied the effect of fins length of heatsink on the performance of the processor type Athlon XP+ 1.73GHz .First a common heat sink had ben used, then the reads of the processor it's temperature and heat emission at three conditions were taken ,the 1st one at minimum uses of performance just opening windows ,the 2nd one at the average use of performance opening word document with some wrights while the 3rd one is the maximum use of performance of the processor and this occurs when we run a huge software or a complicated high graphics big game. Many programs give us a full condition for any part of the computer especially the processor such as (Norton System Work, Sandra SIS, Windows Vista Task Manager (WVTM)…etc). In this research we used (WVTM) because it's part of the OS vista 119 أحمد عدنان دراسة تأثير طول الزعنفة لمبدد حراري على أداء المعالج من نوع أثلون which will not apply another load upon the processor, also the (WVTM) contains great tools of operations. Also we calculate the time requiring for the OS to boot at this type of heatsink and other applications like office and others. Then we changed the heatsink with another one with fins length twice than the old one. A model of the heatsink were built for both cases by the package (AutoCAD 2008) and analyzed it in the package (FLUENT 6.3) to show the thermal emission inside both heatsinks and the experimental and theoretical results were acceptable.


Article
Experimental prediction of pressure drop and friction coefficient of Gas –solid fluid flow in a circular tube
التنبؤ التجريبي لهبوط الضغط ومعامل الاحتكاك لجريان مائع غاز صلب في انبوب دائري

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Abstract:- This study explains the relationship between friction coefficient and pressure change at a range of Reynolds (21056 - 32033) and (0 -1.4) solid loading ratio of two phase flow (Gas-solid) inside a circular copper pipe of (63mm) inside diameter and (2m) length by using laboratory apparatus and solving the equations mathematically . An experimentally relationships of friction coefficient and pressure change with Reynolds number and flow velocity one obtained also the relationship between the solid loading ratio with friction coefficient and pressure change has been done for a limit range of Reynolds number . It is noticed that the increasing in friction coefficient and pressure change for two phase flow was occurred when solid loading ratio increasing. Also the relationship between pressure change and Reynolds number was direct proportion while the relationship between friction coefficient and Reynolds number were inversely related


Article
OPTICAL PROPERTIES OF SPRAYED TIN OXIDE FILMS
الخصائص البصرية لطبقة اوكسيد القصدير المرشوشة

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Abstract

Abstract This research is intended to study the preparation of heat mirror by spray pyrolysis method. Un-doped tin oxide (SnO2) and doped with 0.09%, 0.9%, and 9%, titanium dioxide heat mirror films were deposited on pre-cleaned substrates. The microstructure characterizations were carried out by x-ray diffraction technique. The optical properties were obtained by UV-Visible spectrophotometer. The un-doped samples have displayed average transmittance value of 73% in the visible region. Whereas, the doped samples of 0.09 and 0.9 mol% TiO2 show a good reflectance values of 76% and 80% respectively in the wavelength of 2700 nm.


Article
AQUEOUS EXTRACT OF LEAVES OF ZIZIPHUS AS AN ECO-FRIENDLY INHIBITOR FOR THE CORROSION OF MILD STEEL IN POTABLE WATER
المستخلص المائي لورق السدر كمثبط ودي للبيئة لتآكل الفولاذ في الماء الصالح للشرب

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ABSTRACT The inhibitive effect of the aqueous extract of Ziziphus leaves on the corrosion of mild steel in drinking water have been investigated by using an electrochemical polarization and weight loss method. The results obtained shows, that, the extract of leaves of Ziziphus could work as an effective inhibitors against the corrosion of steel in drinking water network. The inhibition percentage increases with the increasing of the leaves of Ziziphus concentration at 30°C. The inhibitor percentage efficiency above (98 %) was attained at extract of Ziziphus leaves concentration (1% v/v). The inhibition efficiencies of the extract of leaves of Ziziphus obtained from weight loss method and polarization measurements were in good agreement. electrochemical polarization studies clearly reveal that the extract of leaves of Ziziphus behaves predominantly as an anodic inhibitor. The study also shows that the inhibition efficiency was insignificantly affected by the temperature rise of the medium.


Article
STUDY OF DRY SLIDING WEAR RESISTANCE OF COMPOSITE MATERIALS OF AN ALLOY(AL – 12 % SI) REINFORCED WITH SIC PARTICLES
دراسةمقاومة البلى الانزلاقي الجاف لسبيكة معدنية ذات اساس من سبيكة الالمنيوم 12% سليكون مقواة بدقائق كاربيد السليكون

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Abstract In this study, composite materials of an aluminum alloy(Al – 12 % Si) matrix reinforced with 5wt% SiC particles were prepared by gravity die casting and squeeze casting under casting pressure of ( 38MPa) and mold preheating at temperature (200 oC). Microstructure and hardness for prepared base alloy and composite materials were carried ou. Dry sliding wear type (pin–on-Disc) with variation in applied load was carried out under a constant steel hardness (35 HRC), sliding speed (2.7 m / sec) and sliding time (20 min). It has been found that prepared base alloy(Al – 12 % Si) and composite materials produced by squeeze casting have wear resistance better than that of base alloy and composite materials produced by gravity die casting.


Article
Protective the carbon steel from corrosion by coating (Zn-Ni) alloy
الطلاء بسبيكة اساس (Zn-Ni) لحماية الفولاذ الكربوني من التاكل

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Abstract: In this research an attempt to introduce an additional improvement on the properties of (Zn-Ni) electroplated layer. In this work electrodeposited layer of different thickness of (Zn-Ni) from an alkaline solution is performed on samples of low carbon steel. X-ray fluorescent (XRF) used to determine the chemical composition of (Zn-Ni) deposited layer as well as x-ray diffraction (XRD) technique is used to determine the phases of the electrodeposits layer.

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