Table of content

Journal of Engineering

مجلة الهندسة

ISSN: 17264073
Publisher: Baghdad University
Faculty: Engineering
Language: Arabic and English

This journal is Open Access

About

The Journal Engineering was issued in 1986. It was Stopped from 1990 – 1997 because of the economic blockade. It restarted publication after the fourth scientific engineering conference for it published the papers that were accepted in the conference.
It is a scientific engineering journal refereed by specialized and qualified professors in most of the engineering fields and those Specialists in the issued by the college of Engineering university of Baghdad .It was serenely publibued , but from 2011 it has issued of monthly for the numerous papers submitted to the journal to publish their papers in this scientific journal in addition to some of the Arabs professors because the journal is considered one of the valued journals in the Arabic homelan .
Many professions were the head editor of the journal from its first issue. The first one was prof.dr. Laith Ismail Namiq then prof.dr. Mohammed A.Alawis ,prof.dr.Ali A Al – kilidar prof.dr. Abdul-Ilah Younis and currently Prof.dr.Qais S. Ismail.

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Jadriyah, Baghdad
Iraq
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Email: joengbag@uobaghdad.edu.iq

Table of content: 2008 volume:14 issue:4

Article
SUN SHADOW ANGLES FOR ARCHITECTCS With special reference to The UAE
زوايا ظل الشمس المهندس المعماري

Authors: عبد السلام فرمان
Pages: 519-539
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Abstract

Often the greatest source of heat gain is the solar radiation entering through windows. Heat is then trapped in; because of the "greenhouse effect" shading the windows is one of the most effective method within the reach of the architect for reducing this heat gain. This is nowhere more necessary than in a country like the U.A.E. but we find the architects here often ignoring this important environmental aspect of design. This is partly due to the lack of relevant local meteorological data plus the complexity of the procedure involved ;and partly due to the misconception that such aspect looses much of its significance when the building is air conditioned . The aim of this paper is to simplify the issue and promote greater attention to this aspect by architect designing for the U.A.E. Based on the solar azimuth and altitude angles for the U.A.E. for the representative latitude related to local civil time, a number of useful tables to the architect have been prepared . One gives the hourly shadow angles and direction for each month. Then a set of tables to define the shadow angles for buildings of various possible orientations. In addition effective temperature isopleth for the U.A.E. has been constructed, with the shading line definded on both the isopleths and the solar charts. This is done in order to give greater insight into the overheated period of the U.A.E., and facilitate future possible use of shadow protractor, when necessary.

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Article
مدن الصحراءبين المكونات الايكولوجية والحلول التخطيطية

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Abstract

It seems very clear to us that the great influence of the ecologic component of forming urban texture on the desert cities and the civiled constanity of tropical places in general, but these factors dont represent an aadequit reason of settlement and the process of forming urban society specially when the action of huminity goes farther than reaction to the mentioned factors in away to include its specified properties in that product. This research focuses the accurate interaction between invironment factors and civilization nature as a result in the development of society and develop or built strategies of new fonomenas of desert urbanization.

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Article
مقترح نظام اداري لقواعد اختيار اسلوب التنفيذ في مشاريع قطاع التشييد في العراق

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Abstract

Among the most important problems which faced the new approach is the wide use of old approach , particularly the traditional approach ( general contractor ) and the bill of quantity contract, and this were commonly used in the course of the application of fast – track approach in spite of unfulfilling the execution requirements for the fast – track , so It became necessary to look for certain contract rules to be used as a substitute suited all conditions and cases after concluding lessons from the local experiments in rebuilding issues . This research aims at analyzing the subject of shortening time factor taking in consideration the effect all the effective factors which leads to increase the cost and time A scientific methodology was followed in both theoretical and practical phases of the study . A detailed statistical analysis of the study was incorporated using questionnaire and interview method to evaluate the effective factors directly or indirectly on fast – track approach.

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Article
SUSTAINABLE ARCHITECTURE LEVELS
طبقات العمارة المستدامة

Authors: عمار سالم
Pages: 560-583
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Abstract

Sustainable architecture has became one of the most important architectural concepts on earth today because of the energy crises. Architecture is concerned as the largest energy consuming field ,so that one of the main goals of modern architecture is to reduce energy consumption or reticence it from building if possible . Sustainable architecture is a modern and new concept. It is used sometimes to refer to green ,intelligent and environmental architecture , and that make it confused term , therefore the main goals of this research is to clear the main important pillars of this architectural concept (reduce costs , reduce the environment pollution , reserve energy ) as a first goal. Second goal establishing The Procedural definition for this architectural concept is sustainable architecture is Defined In This Paper As (The Architecture That Satisfies The architectural human needs) – beauty , function , structural needs , the ability to generate energy needed to operate the building or reduce the energy needs for it , reduce the costs of production & maintenance , consumption for environmental conservation purposes to preserve earth and its resources for the future generations. This paper tried also to classify the concept to different levels each one dedicated to specified architectural field . Intelligent sustainable architecture is the one that depends on modern technologies for implement the sustainable concept .Green sustainable architecture is the architecture using plants and green areas ,environmental sustainable architecture is the one depending on environmental features to achieve sustainability. and so on for the rest of levels concepts . As a summery this research is an attempt to understand the concept ( sustainable architecture ) and recognition for its interrelated levels.

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Article
Alternate Sliding Friction Formulations of Elasto - Hydrodynamic of Spur Gears

Authors: Abbas F. Abbas Al-Zubaidi
Pages: 2928-2939
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Abstract

In this paper, several sliding friction formulations used in spur gear dynamics are examined and compared in terms of the predictions of interfacial friction forces and off-line-of-action. Computing friction formulations include Coulomb models with time-varying friction coefficients and empirical expressions based on elasto - hydrodynamic and/or boundary lubrication regime principles. Predicted results compare well with friction force measurements and appeared completely conformed with specific objectives of this paper are established as follows: (1) propose an improved MDOF spur gear pair model with time-varying coefficient of' friction, µ(t), given realistic mesh stiffness profiles.(2) comparatively evaluate alternate sliding friction models and predict the interfacial friction forces and motions in the off-line-of-action (OLOA) direction: and (3) validate one particular model (III) by comparing predictions to the benchmark gear friction force measurements


Article
Theoretical and Numerical Analysis of Fuel Droplet Combustion Process with Conventional and Transient Models

Authors: Ali Sabri --- Basma Abbas Abdul Majeed
Pages: 2940-2958
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Abstract

The study introduces a theoretical analysis and numerical solution for the combustion of a hydrocarbon fuel droplet inside the combustion chamber. The study employs two mathematical models to analyze the combustion process. Conventional (Classical) model and Transient model. The combustion process of a stagnant droplet in the steady state was analyzed in the classical model, while, In the transient model, it was assumed that there is a period of time in the stages of the droplet combustion in which the droplet is heated before combustion. The effect of change in temperature on the thermo-physical properties of the fuel was adopted through the two models. For the classical model, a convenient approximation was adopted for the heat transferred inside the droplet.

Keywords

droplet --- combustion --- numerical --- modeling --- transient.


Article
Study of Drop Size Distribution in RTL Contactor

Authors: Yahya J. Jany --- Adil A.A. Al-Hemiri
Pages: 2959-2974
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Abstract

The present work studied the drop size distribution in the RTL contactor using two liquid-liquid systems, xylene-acetone-water and kerosene-acetone-water. Process variables studied were: rpm (10-50 min-1), continuous phase flow rate (4-12 l/h), dispersed phase flow rate (4-12 l/h), and concentration (0.1-0.5 mole/l). It was found that Sauter mean drop diameter (d32) decreased with increasing rpm and continuous phase flow rate, and decreasing dispersed phase flow rate and concentration. An empirical correlation, with a correlation coefficient equal to (92.6%), relating d32 with process variables was developed having the form:

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Article
Comparative Study of Traditional Pwm Inverters and Multilevels Inverters

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Abstract

The need of higher powers in electrical drives has forced the researchers to develop new power source possibilities. Multilevel inverters have been presented as a cost effective solution for various high voltage and high power applications including power quality and motor drive problems. The traditional pulse width modulated (PWM) Inverter does not completely eliminate the unwanted harmonics in the output waveform. Using the multilevel inverter as an alternative to traditional PWM inverters for electric motor drive applications is investigated. The concept of the Optimized Harmonic Elimination Stepped-Waveform (OHESW) technique for a multilevel inverter is presented. The effectiveness of this technique in minimizing the inverter switching losses and its output voltage harmonic content which cause reducing harmonic losses and torque pulsations of an induction motor fed form is investigated analytically. Comparison between the Selective Harmonic Eliminated PWM (SHEPWM) as a traditional PWM technique for three-level inverter and the OHESW technique for multilevel inverter with regard to the switching losses, harmonic distortion, additional harmonic losses in the motor and the pulsating torques is also presented.


Article
Computer Aided Design and Implementation of Converter Circuits Applied for Photovoltaic

Authors: E. AL-Shakarchi --- K. AL-shara --- Z. M. Kubba
Pages: 2990-3000
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Abstract

This research intents to design and laboratory implementation of a power electronic converter, which is useful for home applications, industrial, communications, street light and water pumping using solar cell source. The design is based on a step up boost DC/DC converter followed by a full wave SPWM inverter. The nominal power rating is 1.25kW and can operate from any DC source such as DC battery besides fuel cells. The system which consists of the following stages (PV, converter, inverter, DC link, filter and snubber circuit), is designed primarily with a general module depending on Orcad PSPICE program to produce power output nearly 1.25kVA at 50Hz with a pure sinewave output for both voltage and current. After designing and simulating this system, the intended SPWM inverter are built experimentally to compare its results with the simulated one.

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Article
Increasing the Output Voltage of Pwm inverter Using Harmonic Distortion

Authors: Ahmed .Refaat --- Q.Abed alhassan --- Mohammed Hussen
Pages: 3001-3011
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Abstract

By adding a measure of third harmonic to the output of each phase of three-phase inverter, it is possible to obtain a line-to-line output voltage that is 15 percent greater than that obtainable when pure sinusoidal modulation is employed. The line-to-line voltage is undistorted. The method permits the inverter to deliver an output voltage approximately equal to the voltage of the ac supply to the inverter. Thus an induction motor of standard rating with respect to the ac supply to the inverter can deliver very nearly full power at rated speed when supplied from the inverter. This is achieved without pulse dropping or any other form of mode changing.

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Article
Investigating the Effect of Iron Presence in the Magnetic Circuit of A double Helical Winding Induction Motors

Authors: Saad Mahdi --- J.H. Alwash
Pages: 3012-3019
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Abstract

The paper presented a new type of double helical-winding tubular induction motor (DHWTIM). The proposed motor consists of double- layer helical windings primary arranged on the same circumference with a common secondary. By controlling the phase sequence of supply voltage for each of primary winding layers, the secondary conductor would be capable of producing pure rotary motion, pure linear motion, or helical motion. An appropriate multi-layer analysis using cylindrical geometry is presented. This has been used to study the effect of iron presence in the magnetic circuit of the machine on its performance.


Article
Evaluation of the Performance of the Dora Refinery Wastewater Treatment Plant

Authors: Muwafaq A. Abed --- Rafa H. Al-Suhaili
Pages: 3020-3035
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Abstract

Oil refineries are major contributors to local environmental problems .The main pollutants are oil , dissolved components , spent acids , suspended solids, sludge . Technically it is possible to remove all these pollutants by Physical , chemical and biological means .Oil is initially removed in the (API) separators , by skimming, while the heavy particles by scrapping . Further removal of discrete particles is done by gravity settlement in the primary settlement tank .The remaining suspended matter is removed by chemicals , that are added in the flocculation tank , while further flocs are removed in the air flotation tank . The biological treatment follows to remove the biological pollutants , usually followed by secondary settlement to reduce the flux of suspended particles carried with the effluent water. This thesis deals with the Dora refinery wastewater treatment plant , its present performance in comparison with the designed treatment performance and its final effluents compared with the Iraqi discharged water quality limitations .In order to identify the characteristics of the refinery effluents and to evaluate the performance of the refinery wastewater treatment plant , wastewater from different treatment stages were analyzed for various physical and chemical parameters . Using these parameters as the criteria of performance , comparisons were made between the actual and the designed performance for various potential pollutants. The sampling was conducted during 6 months from May to October 2006 , with two samples in each month for each of the units, one before , and one after.The results showed that the wastewater treatment plant in Al-Dora Refinery performed significantly, where high removal efficiencies , were obtained. For T.S.S , Oil , COD , BOD , Sulfide and Phenol which were 95% , 88% , 86% , 81% , 85% and 97% respectively . And the plant was not very efficient in NH3 , SO4 and PO4 removal .


Article
Using Fuzzy Logic Controller for A two- Tank Level Control System

Authors: Omar W. Abdul-Wahab
Pages: 3036-3047
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This paper presents a fuzzy logic controller for a two-tank level control system, which is a process with a dead time. The fuzzy controller is a proportional-integral (PI-like) fuzzy controller which is suitable for steady state behavior of the system. Transient behavior of the system was improved without the need for a derivative action by suitable change in the rule base of the controller. Simulation results showed the step response of the two-tank level control system when this controller was used to control this plant and the effect of the dead time on the response of the system.


Article
Sliding Mode Vector Control of A Pwm Inverter Fed Induction Motor

Authors: Azzam M. Ahmed --- Qais S. Al-Sabbagh --- Aymen A. Salih
Pages: 3048-3067
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Abstract

The purpose of this paper is to analyze, study and simulate a three-phase induction motor drive using vector (field-oriented) control strategy and PWM current regulated inverter using hysteresis band current controller. The mathematical model of the induction motor and the principle of indirect field-oriented control are introduced. The Sliding Mode Controller with Boundary Layer (SMC-BL) is used as a speed controller and compared with the proportional integral (PI) controller. A Simulink / Matlab program is written for simulating the induction motor model, SMC-BL and PI controllers and indirect field oriented control. The SMC-BL based system and PI-controller based system are compared from the point of view of speed–time response and load disturbance. The simulation results which illustrate the performance of SMC-BL based system and PI-controller based system are plotted and discussed. These results obtained have shown improvement in the SMC-BL system performance from the point of view of variable speed tracking and load disturbance


Article
Skin Friction Between Undisturbed over Consolidated Silty Clay Soils and Concrete

Authors: Zuhair Kadhim JahanGer --- Azad Abbas Ahmed
Pages: 3068-3076
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Abstract

Up to date, in many foundation design problems (especially for piles foundation), the shear strength (skin friction) between soil and construction materials of the foundation was usually estimated or correlated without any direct methods for measurement. The modern trend is to establish skin friction coefficients through laboratory experiments in which the factors influencing the results may be controlled quantitatively. In this study strain controlled Direct Shear Tests were performed using shear to simulate the shear behavior area between concrete (foundation materials) and undisturbed over consolidated silty clay, to determine the shear strength of soil – foundation interface, considering the following variables : (1) Concrete, smooth surface condition, (2) Undisturbed over consolidated silty clay, (3) Variation of the normal load between the friction surface. The tests conveniently revealed both shear strength parameters as for soil test (cohesion and angle of internal friction), and interface angle of friction was in the range of 14° to 17°, while the adhesion was in the range of 13 to 16 kPa. The ultimate shear strength was mobilized through 4 to 7 mm displacement in the direction of shear slip; this was a great advantage of Direct Shear Test performance.


Article
Leaching Behavior of Gypseous Soils

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Abstract

A series of laboratory tests were carried out on disturbed soil samples containing different gypsum contents. The soil samples were obtained from al-Jazeera south-west of Iraq. Tests were performed to obtain the physical and mechanical properties of the soil. In addition; permeability-leaching tests were conducted by using oedometer and large-scale Rowe cell apparatus to obtain the variation of the coefficient of permeability, dissolved gypsum and leaching strain with time. All samples were tested under similar conditions, e.g. the hydraulic gradient, vertical stress and leaching period. The soil samples designated N1, N2, and N3 are obtained from depths (0.5-0.75), (1.0-1.25), and (3.25-3.5) m and having gypsum content (31.43), (51.37), and (4.86) percentage respectively. Results of experimental work show that the coefficient of permeability, the percentages of dissolved gypsum and leaching strain measured from the oedometer test are higher than that measured from large-scale Rowe cell test for the same soil sample. The gypseous soil with higher gypsum content exhibited significant amount of leaching strain.


Article
Sectional Curvature Ductilty of Reinforecd Concrete Columns Under Large Inelastic Deformation

Authors: Raad K. Al-Azawi
Pages: 3090-3098
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A mathematical model is developed to express stress-strain relationship of normal-strength concrete confined by transverse reinforcement. The sectional ductility analysis on rectangular reinforced concrete columns is performed under axial load. Analytical modals available in the literatures for confinement concrete by different types of transverse reinforcement are used. A parametric study is performed to study the influence of these parameters on the curvature ductility of reinforced concrete columns. The main parameters introduced are the amount of longitudinal reinforcement, amount of transverse reinforcement, tie spacing and the level of the compression axial force. The experimental and analytical results available in the literatures are being compared with present study.


Article
Static and Dynamic Analysis of Stiffened Plate Used in Machine Tool Column

Authors: Wedad I. Alazzawy
Pages: 3099-3111
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Static behavior (under torsion and bending loading) of machine tool column was studied in this paper. The effects of changing the cross sectional area of the column itself on the deformations (design parameters) was investigated. The adding of stiffeners and changing the stiffeners cross sectional area are also verified. The results show that using of stiffeners can produse a great reduction in deformation of the column structure under the stastic loading mentioned above. Also using stiffeners with different cross-sectional areas suggest the best stiffener cross-sectional shape can be used to give the minimum deformations of column structure. Dynamic analysis of column involves calculating natural frequencies and mode of different column structure mentioned above, these frequencies are fairly insensitive of adding stiffeners to colmn structures.


Article
Capability of Forging Technique to Produce Round Shape Flange Using (POM) Material Under Cold and Hot Conditions

Authors: Talib.H.Rashid
Pages: 3112-3120
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The paper studied capability of forging process to produce round shape flange using acetal (celconR¬) polymer which is an engineering crystalline material having a good ductility if it is preheated The process done under cold & hot conditions This kind of technique guarantees a product with high strength and stiffness better than what injection molding could achieve. The products showed crack and curling traces on the flange under cold forging, but a good product was achieved by heating the billet and the tools to (100Co)with improvement in the mechanical properties. The paper discussed also through (stress – strain) curves manner of deformation through forging action. The results explained that POM (celconR¬) is forgeable polymer if it is preheated at (100 Co ) using slow speed press by closed die forging process under applied pressure of 170Mpa to produce round shape flange, while this technique failed to forge same polymer at room temperature.

Keywords

Forging --- POM --- recovery --- dwell time --- billet --- SPF.


Article
Simulation of Scheduling Production System by Using Integrating Simulation Models with Artificial Neural Network Model

Authors: Z. I. AL-Daoud --- Ouf A. Shams
Pages: 3121-3135
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Traditional methods of dealing with finding the relationship between the inputs data of simulation models and the outputs data fail or takes a long time to find this relationship. Artificial neural networks (ANNs) have the ability to learn complex relationships between inputs and outputs. Their use can greatly enhance simulation models and allow for more accurate representations of real life scenarios. This paper is concerned with the application of the mechanism of integrating simulation models with artificial neural network (ANN) model. This mechanism was tested by integrating simulation models of re-tubing heat exchangers line (RTHEL) with ANN model to schedule entering exchangers to inside re-tubing workshop. The result of applying this mechanism of integration in system (RTHEL) was in reducing completion time of re-tubing batches of heat exchangers by about (12.5%).


Article
Computational Method for Unsteady Motion of Two-Dimensional Airfoil

Authors: Anmar H. Ali
Pages: 3136-3152
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A numerical method is developed for calculation of the wake geometry and aerodynamic forces on two-dimensional airfoil under going an arbitrary unsteady motion in an inviscid incompressible flow (panel method). The method is applied to sudden change in airfoil incidence angle and airfoil oscillations at high reduced frequency. The effect of non-linear wake on the unsteady aerodynamic properties and oscillatory amplitude on wake rollup and aerodynamic forces has been studied. The results of the present method shows good accuracy as compared with flat plate and for unsteady motion with heaving and pitching oscillation the present method also shows good trend with the experimental results taken from published data. The method shows good results for a wide range of unsteady motion of a two-dimensional airfoil.


Article
Influence of Rubber Constituents on Performance of Asphalt Paving Mixtures

Authors: Ayad A. F. Al-Dulaimi
Pages: 3153-3164
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Environmental problems created by discarded waste rubbers, such as potential fire and disease hazards, have become significant in recent years. In connection with rubber recycling, a comparative study of laboratory performance of application of two polymer types: styrene butadiene rubber (SBR) and polyethylene–vinyl acetate (PVA) in asphalt paving mixtures is presented. These mixtures are usually employed in construction the surface courses in Iraq. These modified asphalt mixtures were prepared with asphalt cement previously modified by using three percents of polymer (1, 3 and 5) percent by weight of modified asphalt. Two control mixes are adopted for comparison purpose. The first control mix was produced with 40/50 penetration asphalt cement while the second was produced with 60/70 penetration asphalt cement. To evaluate the mixture characteristics of the modified and conventional mixes: laboratory tests of Marshall, indirect tensile strength, indirect tensile resilient modulus, indirect tensile fatigue and incremental indirect tensile creep were conducted on a compacted Marshall specimens. The VESYS 5W software program was used to investigate the effect of polymer type on rut depth occurring in whole selected pavement structure. The results of the present study indicated that the modified mixtures exhibited higher tensile strength characteristics than the control mixtures. The modified asphalt mixtures showed overall better performance indices (rut depth and fatigue cracks) than the corresponding control mixtures. Also, the addition of (SBR) polymer type to the mixture improves asphalt mixture performance, especially, when it is added by 1 % by weight of asphalt.


Article
Derivation OF STIFFNESS Matrix for A general Two Dimensional Curved Element in General Global Coordinates System

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In present paper, the derivation of stiffness matrix for a general two dimensional curved element in the global coordinates system is presented. The derivation depends on the assumption that any curved in-plane element can be approximated by a specified curve in polar coordinates. The polar curve assumed in this polar depends on some variables that enable it to represent any two dimensional curved element. The derivation process accompanied by complex integrals which are evaluated by using (Gaussian Quadrature) method of numerical integration. One numerical example is presented to verify the accuracy and efficiency of the derived stiffness matrix. Very good agreement is obtained between the results of the derived stiffness matrix and the results of the exact model.


Article
Prediction of Induced Stresses within Soil Mass Using Artificial Neural Network

Authors: Abdul Kareem Esmat
Pages: 3179-3197
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In this paper, an Artificial Neural Network (ANN) is applied to predict the soil stress within a soil mass for a variety of depths and displacements under applied loading. The neural network model is created and applied for two cases, point load, and Uniform rectangular load. Theses two cases were selected among many other cases of loading as a representation of the capabilities of ANN in finding proper solutions. The first case needs one input to get one output, where in the second case we need two inputs, to get one output only. Results revealed that function approximation using neural network can be applied easily and can give accurate results by choosing the appropriate learning algorithm, number of layers, and number of neurons to solve the problem. ANN model can provide reasonable accuracy for civil engineering problems, and a more effective tool for engineering applications.


Article
Improvement of Soil Using Geogrids to Resist Eccentric Loads

Authors: Faris W. Jawad --- A'amal A. Al-Saidi --- Mosa J. Al-Mosawe
Pages: 3198-3208
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This paper presents the results of experimental investigations to predict the bearing capacity of square footing on geogrid-reinforced loose sand by performing model tests. The effects of several parameters were studied in order to study the general behavior of improving the soil by using the geogrid. These parameters include the eccentricity value, depth of first layer of reinforcement, and vertical spacing of reinforcement layers. The results of the experimental work indicated that there was an optimum reinforcement embedment depth at which the bearing capacity was the highest when single-layer reinforcement was used. The increase of (z/B) (vertical spacing of reinforcement layer/width of footing) above 1.5 has no effect on the relative improvement for the soil and the relative improvement (%) of the reinforced soil can be predicated by using a simple equation .

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Article
Hydrological Modeling Of Assanna’f Marsh

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Abstract

AsSanna'f Marsh is one of the southern Iraqi Marshes. It is considered as a seasonal marsh. During rainy season, the marsh feeders start to fill the nearly empty region of the marsh and the water levels start to increase gradually. After the water level reaches a specific value, it starts to flow toward Al Huwayza Marsh. Studies on the hydrological properties of AsSanna'f Marsh are rare and there is a lack of hydrological data of AsSanna’f Marsh feeders. Generally, this paper was prepared to predict missing hydrological data, a procedure was developed and applied for this purpose, and to be used with the available hydrological and topographical data for modeling and analysis the hydrological properties of AsSanna’f Marsh. The topographical survey and the hydrological field measurements for a period of six months, which were carried out by the Center for Restoration of Iraqi Marshlands, CRIM, of the Ministry of Water Resources, MOR, were used in the hydrological analysis carried out by this paper. The area and storage elevation curves were computed in two different methods satisfying the existing behavior of the flow condition through the marsh. Relations between the inflow, out flow with the water level elevation, and storage and losses within the marsh were obtained. The hydrological routing showed the dykes surrounding AsSanna'f Marsh must be at least 11m.a.s.l to increase the Marsh outflow into Al Huwayza Marsh. especially at the south east boundary of the marsh near Al Msharah River. Maximum and minimum storages and the extended wetted area of the marsh were specified. The required inflow and outflow of AsSanna’f Marsh was studied, taking in consideration the wet, normal, and dry years. The maximum allowable AsSanna’f Marsh inflow into Al Huwayza Marsh is specified for flooded year satisfying different the design criteria of the control structures of the outlets of Al Huwayza Marsh and Kmait Flood Escape. A control structure was suggested at the outlet of AsSanna’f Marsh to ensure the full restoration of Al Huwayza Marsh.


Article
Optimam Shape OF Tapered Columns Under Axial Compressive Force

Authors: Rasha Atwan Faraj --- Ehab Nabil Issa --- Wisam Victor Yousif
Pages: 3230 -3244
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The continuous and rapid development of shapes for architectural members and structural researches development in stability field encourage the designers and researchers to study the effect of member shape on the load capacity. The optimum strength of compression members with economical dimensions can be obtained to satisfy the architectural and technical requirements. A different nonlinear tapered member shapes have been studied under compression axial force with simply supported end conditions. Then graphical comparisons for different member shapes are presented to find the maximum axial force and minimum member volume at buckling state. This study is based on modified stability functions that have been based on Bessel functions. The results of this study provide structural and architectural designers the most proper member’s shape, with more economical dimensions to carry the design load.


Article
Effects Of Skew Angle On Bending Moment's Distribution In The Skew Bridge Deck

Authors: Ghaidak A. Fadhil
Pages: 3245-3256
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In this paper the effect of skew angle on reinforced concrete skew bridges deck is presented by using the grillage analogy. The actual decking system of the bridge is represented by an equivalent grillage of beams. A span 24 m of simply supported right bridge deck with I-section prestressed concrete girders is taken as the case study to obtain the values of the bending moment's distribution for the two types of skewness (types 1 and 2) and the results of skew types are compared against the moments of the right deck span of the bridge. In the skew type 1 the deck span is increased as skew angle increased while in type 2 there is no increase in the desk span. The analysis results for the span are obtained dead and live loads (Iraqi standard load and walkway loading) using STAADPRO computer program. The analysis provided useful information about the variation of moments with respect to change in skewness. It is concluded that in skew bridge deck, the bending moment is increased with increasing the skew angle in skew type 1 while it is decreased with increasing the skew angle in skew type 2 and the negative bending moment in transverse direction and the torsion are increased.


Article
Feasibility Study of Power Saving Based on Using EMMEDUE M2 Building System

Authors: Akram. W. Izzat
Pages: 3257-3267
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The present work concentrates on the feasibility of the heat load reduction by utilizing some structural material with very poor heat conductivity as isolators for heat transmission. Average annular heating and cooling load is estimated for a typical building of certain area and design using ordinary structural material and EMMEDUE M2 building system. The basic element of the new structural material is made of a foam polystyrene core that is self extinguishing and chemically inert with varying density and thickness depending on panel type. The calculations are based on the average maximum and minimum monthly temperature in Baghdad. Building heating load could mainly depend on the average temperature difference per each daily hour per year, while building cooling load components are; direct solar radiation, transmission load, ventilation/infiltration load and internal load. Except the transmission load which depends on the same average temperature difference the other factors could be calculated separately.A reduction of 55% in the annual load is estimated per each house using the new building technology. For a district sums up 1000 houses of the new structural design the total saving of power will be 10.45 MW. The saving in heating and cooling cost is estimated based on capital cost of the diesel generation system and the fuel consumption cost. It has been concluded that the passive structural heat isolation is a very effective manner in countries like Iraq which has severe temperature differences between the summer and winter seasons.

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