Print ISSN: 1813-0526

Online ISSN: 2220-1270

Volume 21, Issue 3

Volume 21, Issue 3, Winter and Spring 2013, Page 1-118

Buckling behavior of aluminum plate with circular and elliptical shapes of central cutout

Raid H. Matti; Dr. Rafi K. Al-bazzaz

Al-Rafidain Engineering Journal (AREJ), 2013, Volume 21, Issue 3, Pages 1-10
DOI: 10.33899/rengj.2013.75426

The present work performs mechanical buckling analyses and experimental investigation on square plates with central cutout with (circular and elliptical) shape and with different size under uniaxial compressive loading, clamped from the loaded sides and free from others. The plates were mostly used in aircraft structures, rocket and automobiles is aluminum alloy (Al-2024 T3) because it has a high strength to weight ratio. The determination of critical buckling load of metallic plate is an important factor in determining the structural stability, which consider the best examination for buckling behavior. Experimental investigation was carried out on square plates by using strain gages. The experimental results for buckling load were compared with analytical results by using finite element structure analysis technique (F.E.M) i.e. using (ANSYS) software. Results have been presented that the square plates with circular and elliptical cutouts decrease in buckling strengths as the cutout sizes were increased.

Durability & Strength of Limestone Used in Building(eng)

SuhailIdrees . A. Khattab; hadeel Mohammed S. Othman

Al-Rafidain Engineering Journal (AREJ), 2013, Volume 21, Issue 3, Pages 1-14
DOI: 10.33899/rengj.2013.75443

The deterioration of limestone rocks selected from three quarries in Mosul city (Baathra, Baghdad street & AL-Warshan), due to different liquids movement inside the pore network was studied. The durability was examined using slake-durability apparatus through wetting _ drying cycles. These cycles induce dissolution, recrystallization and lead to the deterioration of this stone, and finally its effect on the strength of these rocks . Some engineering properties for rocks were studied too.The results showed a clear variation in the properties of limestone between three quarries and within each quarry. The studied Rocks have been classified into two types (weak & strong) according to the properties of these rocks. The results indicated that the rocks subjected to the durability test causes an increases of weight loss, reached to (7.0-14.0%).This test causes alsoa reduction of strength about (15-25%) for these rockswhen treated with distilled water after 10 cycles. In the other hand, differ this range when the specimens rocks were treated with salt solution. This is attributed to variance amount of salt precipitate inside porous stones, due to the various in porosity values for these rocks. Also, the wetting/drying cycles leads to increase in weight loss for specimens due to increase of dissolution/ recrystallization of salts, which apply stress on the wall of porous stones and lead to a weight and strength reduction of the rocks.

Stress Analysis of Steam Turbine Blades at The last Stage in BejiThermal power Station

Dr. Sabah M.J. Ali; Alaa M. Abdullah

Al-Rafidain Engineering Journal (AREJ), 2013, Volume 21, Issue 3, Pages 11-24
DOI: 10.33899/rengj.2013.75431

The low pressure steam Turbine blades are suffering especially the longest parts a bad history of failure. The breakage reasons are unknown due to its complexity. The aim of this work concentrated for the analysis of stresses at the last stage blades in Baji thermal power station. No records have been recorded of breakage incident at any other stages. The aim of the designer is to find way of reducing stresses due to centrifugal force.(ANSYS 12.1) is used for obtaining various stresses in case. Theblades without lacing rod, the blades with lacing rod. It was concluded throughout using (ANSYS) Techniques, analysis increasing stresses at the leading and trailing edge of blade root and a stress concentration at the upper mid of the blade. This indicates why a failure at the lacing rod and aerofoil occurred in this station

Prediction of Soil's Compaction Parameter Using Artificial Neural Network(eng)

RaghdanZuhair Al-saffar; Dr. SuhailI.Khattab; Dr. salem taib

Al-Rafidain Engineering Journal (AREJ), 2013, Volume 21, Issue 3, Pages 15-27
DOI: 10.33899/rengj.2013.75444

This research tackles the feasibility of using Artificial Neural Networks to capture nonlinear interactions between various soil parameters.In this study an attempt was conducted to predict the compaction parameter (γdmax& O.M.C) using database comprising a total of 177 case records of laboratory measurements.
Eight parameters are considered to have the most significant impact on the magnitude of compaction parameters have been used as the model's inputs; liquid and plastic limits,plasticity index, specific gravity, soil type, gravel, sand, and fines content. The model output is the maximum dry unit weight and optimum moisture content.
A Multi–layer perceptron trainings using the back–propagation algorithm, are used in this work. A number of issues in relation to ANN's construction such as the effect of ANN's geometry and internal parameters on the performance of ANN's models are investigated.A parametric study was conducted for the three models to investigate the effect of the input variables on the output of the model.
Based on statistical criterion, it was found that ANN's have the ability to predict the compaction parameter with a good degree of accuracy.

Keywords: soil, Compaction parameter, Artificial Neural Network (ANN), Back–Propagation Algorithm, Matlab..

StudyTheEffect of Speed, Impinging Angle and Slurry Concentration on Erosion of Stainless Steel -316L

Hazim Mohammed Matloob; Abdulhaqq A. Hamed

Al-Rafidain Engineering Journal (AREJ), 2013, Volume 21, Issue 3, Pages 25-34
DOI: 10.33899/rengj.2013.75436

The main aim of the present research work is focused on the influence of key parameters, such as; impinging angle, rotational speed, and concentration of sand in water on the behaviour and characterization of erosion process of stainless steel-type 316L. In the current study, special erosion testing machine has been designed and constructed locally conforming to standard specifications. It was observed that, at a given impinging angle, concentration, and rotational speed, the variation of volume loss withaccumulative distance is generally linear and the erosion rate has been determined from the least square fit of the variation of erosion volume loss with accumulative distance. It was found that increasing the impinging angle increases initially the extent of erosion rate and reach maximum rate at angle of 60o. However, at higher impinging angle, there is a significant decrease in the erosion rate. The erosion rate increases considerably with increasing rotational speed from 550 r.p.m. to 1520 r.p.m.. It was also observed that increasing the concentration of sand particles to about 30 wt.%, increases the erosion rate. In all cases, the erosion rate is near a double after inserting the flow baffles compared to those cases without baffles, and has been attributed to increase of particles rotation and vortices in the flow.

Keywords: erosion; impinging; concentration; vortices.

Seismic Evaluation of Reinforced Concrete Frames Using Pushover Analysis(eng)

Sofyan. Y. Ahmed

Al-Rafidain Engineering Journal (AREJ), 2013, Volume 21, Issue 3, Pages 28-45
DOI: 10.33899/rengj.2013.75445

Ten stories–five bays reinforced concrete frame (two dimensional beams and columns system) subjected to seismic hazard of the Mosul city/Iraq is analyzed. Plastic hinge is used to represent the failure mode in the beams and columns when the member yields. The pushover analysis is performed on the present building frame using SAP2000 software (V.14) to verify code's underlying intent of Life Safety performance under seismic effects. The principles of Performance Based Seismic Engineering are used to govern the present analysis, where inelastic structural analysis is combined with the seismic hazard to calculate expected seismic performance of a structure. Base shear versus tip displacement curve of the structure, called pushover curve, is an essential outcomes of pushover analysis for two actions of the plastic hinge behavior, force-controlled (brittle) and deformation-controlled (ductile) actions. Lateral deformations at the performance point proved that the building is capable of sustaining certain level of seismic load. The building clearly behaves like the strong column-weak beam mechanism, although the formed hinges are in the dangerous level according to Applied Technology Council (ATC-40) categories of structural performance and they need to be strengthened.
Keywords: Building frame, Nonlinear response spectrum, Pushover analysis, Reinforced concrete, Seismic performance.

Variation of Styles in Islamic Architecture and Effects it on The Changing of The Spatial Configuration of Madrasat Buildings

R. S. A. Al numman; D.H. R. Al - omari

Al-Rafidain Engineering Journal (AREJ), 2013, Volume 21, Issue 3, Pages 35-49
DOI: 10.33899/rengj.2013.75437

The phenomenon of unity and diversity is the most important feature that characterized the Islamic architecture, and the Islamic religion had a active role in the creation of this phenomenon.
Muslim architect innovate architecture consistent with the Islamic religion and compatible with the environment and architecture of countries that under Islam .
As the Madrasat Buildings is one of the Islamic architecture types characterized with unity and diversity. From analysis of the previous studies that deal with Madrasat Buildings in Islamic architecture appears that of the evaluating of spatial configuration of these buildings is insufficiency and unclearness according to various Islamic styles . this paper has taken this case as a problem for discussion .
This paper aims to discover the Effects of the Variation of Styles in Islamic Architecture on the Changing of The Spatial Configuration of Madrasat Buildings according to each style . Space Syntax analysis has been applied for a sample of an elected Madrasat Buildings in the different Islamic regions.
The research Investing a group of software as a Space Syntax, this methodology for the rules of spatial configuration as the most objectivity and accuracy for analysis space. The paper divided to two sections, first is a theoretical construction of the phenomenon through the previous literature , whilethe second deal with group of different examples of IslamicMadrasat Buildings through the software to reach a determination of the spatial configuration styles of Islamic Madrasat Buildings. At last the research ends with group of conclusion illustrate the phenomenon in a scientific manner accurate.

Fresh and Hardened Properties of Self- Compacted Concrete at Different Curing Regimes(eng)

M. Abdul-Aziz; J. R. Al-Feel

Al-Rafidain Engineering Journal (AREJ), 2013, Volume 21, Issue 3, Pages 46-58
DOI: 10.33899/rengj.2013.75446

The aim of this study is to compare the properties of three self-compacted concrete (SCC) mixes, with normal concrete mix. For the SCC mixes, the cement was replaced partially with either limestone dust or clinker waste dust. Compressive strength, tensile splitting, and flexural strength tests were conducted at ages of 3, 7, 14, 28, and 56 days to trace the strength development. Modulus of elasticity tests were conducted at 28-days. The test results showed that mixes containing lime-stone dust have better fresh properties than the other SCC mix. The compressive strength test results showed that the mix containing clinker waste powder give higher compressive strength. and mix containing eight percent limestone give higher tensile splitting strength and flexural strength than the mix has ten percent of limestone give for all curing regimes. The results showed that the modulus of elasticity is relatively lower than that for normal concrete and the voids volume in normal concrete is greater than that of SCC.

Keywords: Clinker dust, Compressive strength, Concrete, Fresh properties, Lime-stone

Spatial Sustainability in Historical Urban Centers The role of Spatial Distribution of Mosques in the Spatial Sustainability in Mosul Old City

M.H. Aldewaje; Dr.T.H. Ali; Dr.O.H. Al-Nuaemi

Al-Rafidain Engineering Journal (AREJ), 2013, Volume 21, Issue 3, Pages 50-63
DOI: 10.33899/rengj.2013.75438

The city represents a multi-systems physical entity associated with a range of relationships in various aspects, which organize space, time, meaning and means of communication through many elements. With the vast expanded rising of the concept of sustainability since the last decade of the 20th.Centaury, many trends are adopted in dealing with this concept within the urban environment. The idea of sustainable urban form, which refers to spatial and physical configuration whichaffects urban growth and capable of achieving compatibility with the changing and emerging needs, is the most dominant one. The elements of accessibility, proximity and functional mix are the basic meansof achieving sustainable urban form.
In Islamic city, the mosque was a key element, which urban facilities were gathered around it, it was not just a religious center, but it was an organizer of the spatial configuration of the Islamic city.The multiple functions of the mosque vary from a religious center to a social, political, cultural and educational center. For many Islamic cities, the urban growth has led to establishment of many mosques, where the city of Mosul is a good example for such case. These mosques played the role of multi-purpose centers in the districts they found.
The presented research tries to investigate the role of the spatial distribution of the Friday mosques in Mosul old city until the beginning of the 20th. Centaury in spatial sustainability. This will be done by adopting space- syntax approach and the concept of spatial sustainability focused on the spatial configuration of the city.
Keywords: Friday Mosque, Spatial Sustainability, Sustainable Urban Form, Islamic City, Mosul.

Weight Optimization of Syme Socket Prosthesis

Bakr Noori Khudher

Al-Rafidain Engineering Journal (AREJ), 2013, Volume 21, Issue 3, Pages 59-65
DOI: 10.33899/rengj.2013.75557

In this paper the finite element analysis was achieved on the Syme socket prosthesis to know the possibility of weight reduction of the socket. Previous works were restricted to stress analysis and socket-stump pressure distribution. In this work, the maximum stress induced in the socket model was found out at the maximum load carrying capacity that is developed at push-off stage of gait. The stress calculated is less than the yield and ultimate strength of the socket material, from which the optimum weight of the socket is obtained. The weight reduction of the socket is achieved by decreasing its thickness. At this point, the maximum stress is calculated again at the same loading condition as before reducing the weight. The maximum calculated stress is still less than the yield stress of the socket material. As a result, further weight reduction is achieved and hence the overall cost can be minimized by saving the expenditure on the material. Besides, the patients will feel comfort with light weight sockets.

Key Words: stress, Syme, socket, prosthesis, finite element, weight optimization.

An Assessment of the Impact of Extension on Preservation of The Heritage Mosques in Mosul Old City

Dr.Hassan MahmoodHaj Kasim; Dr.Emad Hani Al-Allaf

Al-Rafidain Engineering Journal (AREJ), 2013, Volume 21, Issue 3, Pages 64-81
DOI: 10.33899/rengj.2013.75440

Heritage mosques of Mosul Old City (MOC) are characterized from other public buildings that it has a permanent function and its need for the extension over time. This renewed and vital need may conflict with preservation of these properties which is a priority of the conservation plan of MOC, however, many of such activities has enveloped a lot of mistakes that led to lose its heritage value, which constitutes a real risk to MOC characteristics.The research aims to assess preservation work performed on elected traditional mosques in MOC, and to define the impact of the expansion need in these buildings. Its phases has been analyzed through personal interviews with those responsible for preservation activities, field studies, and comparison with archive documents, to recognize the level of performing the preservation plans that carried out by participants.We found that most interventions have been carried out with reducing the heritage value of the building, especially when the actor attempted to achieve the extension to provide more space, without considering the principles of conservation theories included in the international charters. Methods, action plans, and strategies have varied due to the variety of official bodies, owners, funders, supervisors and the implementation methods. The final results indicated the absence of public and official awareness of the role of commitment to the standard preservation plans and policies, the lack of personnel experts sector of architectural heritage, and the inefficiency of the supervision provided by direct government authorities, official bodies and institutions to carry out the preservation activities.
Keywords: Preservation, Structural Extension, Preservation Assessment,Traditional Mosques

A Novel Experimental Study of Single–Plane Balancing Method of Crankshaft without Phase AnglesData(ENG)

Mohammed Tariq Sulaiman ِم Abbood Al Taee

Al-Rafidain Engineering Journal (AREJ), 2013, Volume 21, Issue 3, Pages 66-77
DOI: 10.33899/rengj.2013.75561

In real machines, rotating parts are balanced using data of both phase anglesandvibration values. This paper presents an analytical solution of a novel single–plane balancing method using only two test runs oftrial mass without needing to use anydata of phase angles. In addition, a comparative experimental study for each ofthe proposed method and other two methods known as the three test runs andfour test runs has been performed. Throughout this study, an actual arrangement of a crankshaft of an electrical generator has been constructedfor the test purposes,moreover, a computer program based onthe proposed method analysishas been written using (C) Languageto calculate the magnitude and location of the requiredbalancing mass.Thisstudy showed that the proposed balancing method was very effective, practical and saving lots of time, cost and effortas it requires only two test runs.Inaddition, a small vibration meter oflight weight and low cost has beenused to achieve balancing.
Keywords: Single plane balancing, Balancing of crankshaft without phase angles.

Aggregate Production Planning Using Goals Programming(ENG)

Monim A. Gasim

Al-Rafidain Engineering Journal (AREJ), 2013, Volume 21, Issue 3, Pages 78-89
DOI: 10.33899/rengj.2013.75564


This paper investigates Aggregate Production Planning (APP) model in a multi-plant producing multi-product to satisfy portion of fully deterministic demand in several cities for short term planning horizon. A Preemptive Goal Programming (PGP) approach is proposed with different scenarios to solve the APP model with conflicting multi-objective functions in order to maximize the total net profit with limited investment (budget), limited storage space, production capacity, and resources of the company. The proposed PGP model is also used to minimize the total production, inventory, transportation and defective items costs with optimum transportation pattern. A model is optimality solved and validated for a small numeric example of production planning problem with the results of optimal solutions for different scenarios obtained using optimization software LINGO package.

Keywords: Aggregate production planning, Linear programming, Multi-objective criteria, Preemptive Goal Programming, Transportation .

Estimation of Reference Evapotranspiration by Predicting Temperature Values Using a Stochastic Model

Dr.Taymoor A. Awchi; Mr.Ihsan F. Hasan

Al-Rafidain Engineering Journal (AREJ), 2013, Volume 21, Issue 3, Pages 82-91
DOI: 10.33899/rengj.2013.75441

In this research, the stochastic model (ARIMA) was applied to modeling the monthly temperature values for the area of Mosul, Northern Iraq, by utilizing the time-series data of monthly mean temperature for the period (1995-2010) using the Minitab Software.The performance of the proposed model has been approved through the prediction of monthly temperature values for the years 2009 and 2010 where the correlation coefficient value was (R2=0.99) with the values of the actual data for the same years. Then theproposed model was used topredict the mean monthlytemperature values for the years (2011-2012). Due to its importance in the preservation of water resources and rational use in line with the future state of water in the region, this data was used to estimate the future values of Reference Evapotranspiration (ETo) using different empirical methods basedessentially on temperature. The results ofBlaney-Criddle and Hamon methods showed high correlation with ETovalue calculated by Penman-Monteith model.
Key Words: Reference evapotranspiration, Temperature, ARIMA, Time series.

Hybrid Mesh Technique to Model a Deep Bar Induction Motor Using Time Stepping Finite Elements Analysis(ENG)

Prof. Basil M Saied; Ahmed J. Ali

Al-Rafidain Engineering Journal (AREJ), 2013, Volume 21, Issue 3, Pages 90-98
DOI: 10.33899/rengj.2013.75569


This paper presents a 2-D nonlinear transient analysis using Finite Elements Method (FEM) to model a three phase deep bar cage induction motor. Accurate representation for this type of machines has been obtained based on the proposed method. In this model, rotation of the motor has been taken into consideration via use a special algorithm for changing the connection between stator and rotor using the coupled equations. A new approach has been used to reduce the ripple torque produced due to coupled equation between stator and rotor. The produced ripple in rotor bar current also has been reduced, by using different types of element shape to mesh the air-gap and cores of induction motor. The FEM has been tested for wide range of working performance from starting to steady state conditions. To validate the proposed model, a comparison with practical results gives a good verification. The nonlinear properties of the core material have been taken into consideration.

Index Terms: 2-D nonlinear FEM, Induction Motor; Coupling Equations; Performance Parameters.

Optimal Timing of One Supplemental Irrigation

Dr. EmanHazim Sheet; Dr. Nawal M . Jajjo

Al-Rafidain Engineering Journal (AREJ), 2013, Volume 21, Issue 3, Pages 92-100
DOI: 10.33899/rengj.2013.75442

A computer simulation model is developed to study the effect of adding one supplemental irrigation of 75mm on the relative yield of wheat . The growing season of wheat is divided into 26 weeks and a single irrigation is added to any one of the weeks . The model is run for 28 years through the growing season of wheat with two different scenarios for initial water contents in the root zone. The results show that for the first scenario the best single supplemental irrigation is at the first or second or the fifth week, but for the second scenario is at the first or sixth week ,it can be said that with good initial moisture in the root zone at the beginning the best choice is to add single irrigation at the 19thweek.

Khassa Chay Stream Flow Forecasting by Markove Autoregressive AR. Model.(eng)

Dr. Cheleng A. Arselan; Jasim M . Kadir

Al-Rafidain Engineering Journal (AREJ), 2013, Volume 21, Issue 3, Pages 99-110
DOI: 10.33899/rengj.2013.75576

In this research a successfull analysis of the monthly mean of Khassa Chay stream flow record for the period (1941-2001) was adopted, then the Markove Autoregressive AR model was fitted to the resulted stochastic component of the seies, then suitable tests were done to detect the order of the model. Also another decision whether the parameter of this model should be constant or periodic was decided after testing the model. The parameters of this model were found and used to generate the monthly flow for 56 years ahead. It was concluded that Markove AR scheme is adequate to describe the structure of the monthly mean Khassa chay stream flow and the periodic type of this model is more realistic than the constant type because the high sensitivity to errors.

Keywords: Stochastic component , Autoregressive MarkoveAR, Periodic, constant, Model parameters.

Microclimate Performance inDifferent Urban Fabric in Mosul City(eng)

Turki Hassan Ali; Bahjat Rashad Shaheen

Al-Rafidain Engineering Journal (AREJ), 2013, Volume 21, Issue 3, Pages 111-118
DOI: 10.33899/rengj.2013.75578

City of Mosul has a traditional urban core called old city, side by side with a modern fabric adopted by municipal authority since the rapid urbanization which the city had witnessed in the fifties of the last century, the traditional one characterizes with a compact and organic tissue introverted courtyard buildings built with a heavy thick masonry structure, while the modern is open geometric one with wide streets and extraverted buildings build with concrete.
This research aim to make a comparative study for the urban micro climate performance (air temperature and relative humidity) in the two deferent urban fabrics (traditional and modern), during both the hottest and the coldest period of the year, using the meteorological data as a reference for evaluating the performance. The way cities are planned and built is therefore important for the global energy use and environmental comfort. So it’s important to study the relationship between urban form and outdoor climate. The preliminary results confirm that the climatic conditions are much more stable in the traditional city than in the modern part of the city, regarding both air temperature and relative humidity.
Key words:Urban, Microclimate, Fabric.