Print ISSN: 1813-0526

Online ISSN: 2220-1270

Volume 22, Issue 3

Volume 22, Issue 3, Summer and Autumn 2014, Page 1-241


The Effect of Employing Virtual Reality in Architectural Academic Practices

Bayda H. Saffo

AL-Rafdain Engineering Journal (AREJ), Volume 22, Issue 3, Pages 1-18
DOI: 10.33899/rengj.2014.88200

الملخص
لقد عدتالتقنيات المرتبطةبالواقعالافتراضي،مناهمالمخرجاتالخاصةبالثورةالرقميةوتداعياتهاالتكنولوجية،والتياثرتبشكلحيويوفعالعلىعمليةالتصميمالمعماريفيالسياقالاكاديمي ،حيث مكنت هذه التقنيات من تفعيل المنتجات المعماريةباشكالمطابقة للواقع وعرضها في واقعها الافتراضي بهيئات تصورية تفاعلية مجسمة ثلاثيةالابعاد،ذاتية التوجه، متعددة المسارات وغير محكومة بزماناومكانبما يعززالقدراتالتصميمية للطلبة لتعديل وتطوير وتقييمنتاجاتهمالمعمارية من خلال المعاينات التخيلية والموضوعيةواخراجالرسوماتومايصاحبذلك من التحليلات والمقارنات بين مجموعات البدائل التصميمية المختلفة . يناقش البحث الحالياهميةما وردانفاوحقيقة المعرفة النظرية المطروحة عنه في الواقع المعماري لاستخلاص المشكلة البحثية والمتمثلة بعدم وجود تصور معرفي يلم بالمؤشرات الخاصة بمفهوم الواقع الافتراضي بما يمكن من استكشاف تأثير هذه التقنية في واقع الممارساتالاكاديميةالنظرية والعملية في مدارس العمارةوامكانياتهالتقديمالافكاروالبدائلالتصميمية المبتكرة.
وبناءا على هذه الاشكالية البحثية فقد هدف البحث الكشف عن ذلكوتسليط الضوء على الابعاد النظرية لهذه التقنية المتطورة ،وحدود تدخلاتها المستقبلية في سياق العملية التعليمية في اقسام العمارة في ضوء التطورات التقنية لبيئات التعليم التفاعلي، وعلى المستويين، النظري المرتبط بطروحات المقررات للمواد النظرية والمستوى العملي المرتبط بالعمليات التصميمية ،بما يفسر القدرات الخاصة لادوات الثورة الرقمية على ايصال الافكار والمحاكاة، تلك الافكارالتي ماكانت لتتمكن من التعبير عن تشكيلاتها المعمارية والفراغية بطرق وادوات الهندسة التقليدية.اما الاستنتاجات فقد جاءت لتؤكد علىان تفعيل استخدام تقنية تمثيل التصميمات بالواقع الافتراضي، اثرت وبشكل كبير على الممارسات والأفعال التصميمية لطلبة العمارة، وان امكانية المناورة والتنويع في طرح مجموعة البدائل التصميمية ارتبطت وبشكل وثيق بالامكانيات الخاصة لهذه التقنية،فضلا عن ان توظيف مثل هذه التقنيات قد يتطلب احداث تغييرات كبيرة في المناهج وطرق التدريس الخاصة بمادة التصميم المعماري والمواد الاساسية الاخرى ذات العلاقة ، بما يوسع الافاق لخيارات واسعة على صعيد البدائل للنتاجات المعمارية الاكاديمية من خلال تنمية كل من الافكار الابتكارية والحس التجريبي لدى طلبة العمارة.

Evaluation Study of the Election Strategy of the ThematicRoutes in the Urban Renewal Project for Mosul Old Town

Dr. N.T. Alkymakchy; H. H. Alsoofe; Dr. E. H. Alallaf

AL-Rafdain Engineering Journal (AREJ), Volume 22, Issue 3, Pages 19-36
DOI: 10.33899/rengj.2014.88201

الخلاصة
تحاول الدول والحكومات الإفادة من المخزون الحضاري والثقافي الذي تزخر به المدن والمعالم القديمة، وتعمل على تنميته لغرض تحقيق العديد من الأهداف الاجتماعية والاقتصادية.وتتميز مدينة الموصل القديمة بغنى في الإرث الحضاري والتراثي يتمثل في النسيج الحضري والشواخص المعمارية التي تنتشر فيه.وعلى الرغم من أن العراق قد اهتم بالتجديد الحضري للعديد من مدنه منذ أكثر من عقدين من الزمن متخذا وسائل وسبل شتى؛ إلا أن نسبة كبيرة من تلك التجارب لم يكتب لها النجاح،في حين كانت الأهداف المتحققة لما أنجز منها متواضعا بالقياس إلى المبالغ والجهود والوقت المبذول في إعداد الدراسات والتصاميم الخاصة بتلك المشاريع. ولعل جملة الدراسات الأخيرة المتعلقة بالتجديد الحضري لعديد من مدن وقصبات العراق (ومنها دراسة مشروع التجديد الحضري لمدينة الموصل القديمة المنجز نهاية عام2009) مثال واضح على تلك المشاريع التي اهتم بها البلد مؤخرا.ومع أن تلك الدراسة قد قامت بإعداد مسوحات لواقع الحال تبنت من خلالهااستراتيجية تحديد جملة من المحاور (الرئيسية)والتي شكلت شرايين أساسية في هيكل الرقعة الحضرية لمدينة الموصل القديمة إلا أن تلك الإستراتيجية بقيت مبهمة وذات نزعة ذاتية وبعيدة عن واقع حال النسيج الحضري، إذأنتلك الدراسة قدمت رؤية لتحديد تلك المحاور مستندة في ذلكإلىطبيعة تلك المحاور وتواجد مجموعة من الوظائف والفعاليات ضمنها بحيث تعمد لاحقا إلى تطوير تلك المحاور بالاستناد إلى وجود تلك الفعاليات فيها. تحاول هذه الورقة تقويم استراتيجية انتخاب تلك المحاور من خلال المقارنة بين ما توصلت إليه مشروع التجديد الحضري لمدينة الموصل القديمة من ناحية، وما بين واقع حال مسحي لعدد من تلك المحاور من ناحية أخرى، لمعرفة مدى تطابق إمكانيات واقع الحال مع رؤية الدراسة أنفة الذكر وبالتالي تحديد مدى صحة وكفاءة تلك الاستراتيجيات. لقد توصل البحث إلىأن واقع الحال بعيد كل البعد عن ما اقترحته تلك الدراسة في انتخابها للمحاور وبالتالي فان الإستراتيجية التي اعتمدتها خلت من مصداقية الارتباط مع الإمكانيات التي يمكن أن يوفرها الموقع.

كلمات دلالة:الاستراتيجية التصميمية،استراتيجياتهالتجديد الحضري ،تقويمالاستراتيجيات، الحفاظ ، التراث العمراني، مدينة الموصل القديمة

The Concept of Social Sustainability in Schools For the Contemporary Iraqi Architects

Dr. Ali Haider Al-Jameel; Tara A. Abbo al- Yase

AL-Rafdain Engineering Journal (AREJ), Volume 22, Issue 3, Pages 36-49
DOI: 10.33899/rengj.2014.88202

Abstract
This paper tackles the problem of the decreasing social quality of Iraqi schools resulted from repeating school models designed long time ago, despite the world recent socially sustainable schools designs which was affected by profound changes in the fields of education, sociology and psychology culminated by the introduction of the concept of social sustainability. Accordingly, these nececiates parallel developments in the schools design thinking and practicing of the Iraqi architects. This paper intends to answer the question of the nature of the social sustainability concept for the contemporary Iraqi architects as its main problem. The method adopted to tackle this issue includes introducing an adequate theoretical framework of the different aspect of social sustainability in schools, then exploring those aspects for Iraqi architects through a practical study. The conclusions defines the nature of deviation of the local design thinking in comparison with the general theory of social sustainable schools. Then required proposals are recommended.
Key Words:Social sustainability, Schools, Design Thinking, Design Measures, Contemporary Iraqi Architects

Spatial and Visual configurational properties of Traditional Bath Buildings in Islamic cities

Miqdam A. M. Alkurukchi; Dr.Hassan M. Haj Qassim

AL-Rafdain Engineering Journal (AREJ), Volume 22, Issue 3, Pages 50-62
DOI: 10.33899/rengj.2014.88203

Abstract
Recently, researches focused upon traditional public bath buildings (Hammams) in Islamic cities, aiming maintenance and rehabilitation of those buildings that faced negligence due to function miss. Hammam buildings historically had possessed significant social and environmental role, as well as distinguishing them as a unique Architectural type.
The literature review showed lack of concentration upon syntactical properties of the spatial and visual configuration of Hammam buildings.
Accordingly, this paper aims to describe these properties. To attain this, comparative analysis methodology has been adopted between local Baths, and those of other cultures. A number of findings were obtained, explaining spatial and visual properties of Islamic traditional public baths.
Key words: Traditinal Bath, Spatial configuration, Visibility graph

Synthetic CharacteristicsOf Traditional Historic Houses Entrances In Old City Of Mosul

Dr. Emad Hani Ismaeel

AL-Rafdain Engineering Journal (AREJ), Volume 22, Issue 3, Pages 63-83
DOI: 10.33899/rengj.2014.88205

Abstract:
The traditional and heritage houses of Mosul old city have significant architectural value represented by their distinctive characteristics. The main entrances and gates of these buildings with their constructed features located in touch with alleys indicate the building importance and identify the social level of their residents. The paper aims to define the synthetic characteristics and relations of the detailed structural elements constituting the main entrances of the traditional houses in Mosul old city, by gathering, analyzing and classifying these elements in categories according to their architectural details and materials, in order to employ them in providing a digital data base to be used in documentation, reconstruction and conservation activities. The paper also aims to present guidelines and recommendations for creating the virtual objects library for the entire architectural elements of the building in Mosul old city. Research results showthe great diversity of structural elements and synthetic relationships of the heritage houses entrances in Mosul old city, with high harmony between these various elements, referring to the old architects attempts for enriching and improving the alleys heritage facades using architectural elements details, and systematic construction processes.
Keywords: Synthetic characteristics, Entrances, Traditional houses, Built Heritage, Mosul Old City

The Impact of Changing the Entries' Location on the Spatial Configuration Features for the Educational Buildings in the University of Mosul

Amer Abdullah Fathi Al-Azawi

AL-Rafdain Engineering Journal (AREJ), Volume 22, Issue 3, Pages 84-107
DOI: 10.33899/rengj.2014.88204

Abstract
General pre-planning was available only for some buildings of universities in the world. University of Mosul and its buildings are cumulative development university, therefore, many of its old buildings today witness big changes in various of its utilities, and the phenomenon of changing the entries' location of some of its educational buildings may considered as the most important of these changes especially these building are occupied by the same science departments, hence the research problem is defined, which is the fuzziness of the impact of changing the entries' location on the spatial configuration features for the educational buildings in the university of Mosul, due to the importance of the spatial configuration which reflects the human organizing and behaviour that created this configuration, the research aim was defined as trying to illustrate this impact, and some of educational buildings are chosen, which their entries are changed, then their features of spatial configurations are studied before and after change by using the space syntax methodology.
The research reached at the originated entries allowed to increase integration degree and decreasing the depth rate value for theeducational administrative and servant departments in their relation with exterior on the contrary of the particular part of the teaching staff rooms in the research buildings sample.

Lowflowmodeling for Greater Zab and Lesser Zab riversin Northern Iraq

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

AL-Rafdain Engineering Journal (AREJ), Volume 22, Issue 3, Pages 108-120
DOI: 10.33899/rengj.2014.88206

Abstract
This research analyzes the minimum daily flows of each month for 52 years from Eskikalak and Dokan gauge stations onGreaterZabriverand Lesser Zab river respectivelyto predict their lowflowsusingtwo Stochastic Models;(ARIMA)model (Autoregressive Integrated Moving Average) and (Thomas-Fiering)model.A comparison is conducted for the results of both methodsutilizing theMean Average Error(MAE) and Root Mean Square Error (RMSE)ofpredicteddatafrom bothmodelsto verify theirperformanceandreliability. The results showed that the ARIMA model has given more appropriate forecasts and harmonic direction comparing to the same historical time series than those given by (Thomas-Fiering)model. Minitab version 14package is utilizedto assess the statistical side of the research.
Key word: Lowflow, GreaterZab, Lesser Zab, ARIMA, Thomas-Fiering

The Effect Of Magnetic Field On The Performance Of Irrigation Emitters When Using different concentrations of saline water

Dr.Anmar A.AL-Talib; Azeza Ali Mohammad

AL-Rafdain Engineering Journal (AREJ), Volume 22, Issue 3, Pages 121-135
DOI: 10.33899/rengj.2014.88207

Abstract
Many modern researches indicate the effects on water when it is exposed to magnetic fields that effect some waters chemicals and physical properties.
Paper Included a number of experiments during the winter when the water temperatures of 7 to 16 degrees Celsius and the end of the spring season when water temperatures from 26 to 39 to study the effect of the use of several intensities of magnetic field (water liquefaction (0), 500, 1000, 2000.4000 ) Kaus to drain the water out of the rasters using saline irrigation water in several levels of salinity which (tap water (250), 500, 1500, 4000) (mg / l).
The results showed that there is an overlap between the effect of temperature and workmanship changes prevented without knowing the exact impact of the intensity of the magnetic field and nevertheless note that the discharge of drippers improved to the increasing of the intensity of the magnetic field and temperature change has a direct impact on the outside of the discharge emitters.

Effect of Emitter Spacing on The Three -Dimensional Wetting Pattern

Mohammad Tariq Mahmood

AL-Rafdain Engineering Journal (AREJ), Volume 22, Issue 3, Pages 136-146
DOI: 10.33899/rengj.2014.88208

Abstract

Most studies and researches that deal with the effecting factors on wetting pattern under linear dripping source rely on tracing wetting front in two dimensions only. This does not describe the advance of the wetting front in the field by independent or overlapping wetting patterns with three orthogonal dimensions. The current study aims at estimating and observing the resulted wetting pattern from a single emitter on one hand, and the resulted wetting pattern from two neighbored emitters separated by a certain space in three orthogonal dimensions depending on the resulted wetting pattern from a single emitter on the other hand. Six experiments were executed using two water flow rates which are 2.8 and 4.8 let/hr for three cases namely; the single emitter, and two neighbored emitters spaced with 30 cm and 40 cm respectively.
The study revealed that the vertical advance at the midpoint of the two emitters increases 100% when the volume of water flow is increased by 75%. It decreases 14% when the water flow rate is increased by 70%. It decreases by 70% when the emitter spacing is increased by 80%.
Key words : Overlapping wetting pattern, emitters, three orthogonal dimensions

Effect of Recirculation Ratio, Organic Loading and Suspended Solids Loading on the Efficiency of the Trickling FiltersWith Plastic Media

Dr. K. K. Al-Ahmady; E. S. M. AL-Dabag

AL-Rafdain Engineering Journal (AREJ), Volume 22, Issue 3, Pages 147-157
DOI: 10.33899/rengj.2014.88209

Abstract
In this research, an experimental laboratory plant was constructed in order to evaluate the effect of recirculation ratio, organic loading and suspended solids loading on the removal efficiency of trickling filter with plastic media. The plant consisted of four biological trickling filter which were similar in shape, each with a volume equal to (35 liters). Synthetic wastewater was used to operate the plant. To study the impact of recirculation ratio on the system, three of these plants (first, second and third) were operated on recirculation ratio of (100%, 200% and 300%) respectively, whereas the fourth operated without recirculation. To study the effect of increase organic loading, the study program was divided into nine stages, in the three continuation following stages the organic loading rate was steady then increasing in the three suffix continuation following stages thus until ultimate ninth stage, beginning with (1.5 kg COD/m3.day) then (2.1 kg COD/m3.day) and up to (2.7 kg COD/m3.day). The results of the study revealed that; theremoval efficiency of the biological trickling filter increase when the recirculation operation was exist, and the efficiency increased when increase recirculation ratio, so the average efficiency of first stage removal of organic loading was in the trickling filters (first, second, third and fourth ) (84.5%, 86.3%, 87.5%, 80%) respectively. The results also showed that; increasing organic and suspended solid loading decreases removal efficiency of organic matter, ammonia and phosphate.

Suspended Particulates Levels in the Left Bank Residential Areas of Mosul City and Its Relation with Some Meteorological Factors

Abdulmuhsin S. Shihab; Taha A. Taha

AL-Rafdain Engineering Journal (AREJ), Volume 22, Issue 3, Pages 158-164
DOI: 10.33899/rengj.2014.88210

Abstract
This research aimed to detect suspended particulate levels in Mosul city for the first time, as the previous studies depend on dustfall. The city was exposed in the last years to high levels of suspended particulates with the wind blowing. Many studies have found the risk of dust inhalation especially the very fine one. The measurements was conducted using Haz Dust-1100 device, including air temperature and wind speed during the study period from January to September 2010. The average suspended particulates of size 50 micron or less reached 230.8 microgram/m3 with a standard deviation of 210 microgram/m3 in the residential areas, which was higher than the allowable range of 200 microgram/m3. The months April, May and June recorded the higher levels of suspended particulates above the allowable level, while the lower levels was recorded in the cold rainy months January and February. The data analysis showed a significant inverse relationship between wind speed and suspended particulate levels of 50 micron size or less and significant direct relationship with air temperature. The research recommended to make a green belt around the city and increase the green areas to decrease the suspended particulate levels.
Key Words: Suspended Particulate, Dust, Wind speed, Air temperature, Mosul, Residential

The Atmospheric Corrosion of Carbon Steel and Cast Iron in the Environment of South Mosul

Nadum Ibrahim Naser

AL-Rafdain Engineering Journal (AREJ), Volume 22, Issue 3, Pages 165-175
DOI: 10.33899/rengj.2014.88211

Abstract
The carbon steel and cast iron are widely used metals in engineering and industrial applications. In this study, samples of carbon steel and cast iron chosen and distributed on six selected sites in the southregion of Mosul city in Iraq, Because these sites distinguished by the existence of natural emanations of hydrogen sulfide gas is produced and the existence of materials that cause metal corrosion like sulfates and chlorides. The corrosion measured by weight loss method according to the standard (ISO 9223:1992) and the higher rates registered in the sites that contain high emanations of hydrogen sulfide gas and sulfates and chlorides. In addition, it became obvious that there is a relationship between the corrosion exposure time and the corrosion rates which decreased by increasing of corrosion exposure time and continuous increasing in weight loss. The test continued for a complete year.

Heat Characteristics and Performance of Longitudinal Fin Exposed to Wet Air

Ziad M. Al-Makhyoul

AL-Rafdain Engineering Journal (AREJ), Volume 22, Issue 3, Pages 176-185
DOI: 10.33899/rengj.2014.88463

Abstract
A numerical study of the performance of longitudinal fin exposed to wet air has been carried out using finite difference technique. The temperature distribution over the fin surface was determined by using a third-degree polynomial correlation for the relationship between dry bulb temperature and humidity ratio for the saturated air at relative humidity of (0, 25, 50 and 100)% and length of fin from (0.01 to 0.1)m. Also, fin efficiency, fin effectiveness and heat transfer have been calculated. The effect of the atmospheric pressure was also considered. The study showed that the fin effectiveness and fin efficiency of a fin in the case of fully wet fin was found to be smaller than those in the dry fin and the temperature gradient at the tip for a dry fin was greater than that for the wet fin.

Key words: Longitudinal fins, relative humidity, heat transfer

Natural Convection Heat Transfer In Trapezoidal Enclosure with Baffles Attached to Heated Wall

Ziad M. Al-Makhyoul

AL-Rafdain Engineering Journal (AREJ), Volume 22, Issue 3, Pages 186-197
DOI: 10.33899/rengj.2014.88212

Abstract
A two-dimensional solution of natural convection heat transfer in a trapezoidal enclosure using baffles attached to hot wall has been analyzed numerically. The vertical and inclined walls of the enclosure are isothermal while the bottom and top horizontal walls are insulated and the temperature of the vertical wall is higher than the temperature of the inclined wall. Governing equations are solved using the finite difference technique. The study included three cases: one baffle at position 0.5, two baffles at positions 0.2 and 0.5, and three baffles at positions 0.2, 0.4 and 0.6, in addition to Rayleigh number 103, 104 and 105 and baffle length of 0.2, 0.3 and 0.4 used as governing parameters that are effective on heat transfer and fluid flow. Results for the mean Nusselt number, and contour maps of the streamlines and isotherms are presented. It is found that Nusselt number is an increasing with increasing in Rayleigh number while decreasing with increasing in the baffle length and number of baffles.
Key words: Natural convection, Trapezoidal enclosure , Heat transfer , baffles

Automatic Brain MRI Slices Classification Using Hybrid Technique

Dr. AhlamFadhil Mahmood; Ameen Mohammed Abd-Alsalam

AL-Rafdain Engineering Journal (AREJ), Volume 22, Issue 3, Pages 198-212
DOI: 10.33899/rengj.2014.88213

Abstract
This paper presents an intelligent classification technique to identify normal and abnormal slices of the magnetic resonance human brain images(MRI). The prtoposed hybrid technique consists of four subsequent stages; namely, dimensionality reduction, preprocessing, feature extraction, and classification. In the initial stages, the enhancement and removed unwanted informationare applied to provide a more appropriate image for the subsequent automated stages. In feature extraction stage, the most efficient features like statistical, and Haar wavelet features are extracted from each slice of brain MR images. In the classification stage, initially performs classification process by utilizing Fuzzy Inference System (FIS) and secondly Feed Forward Neural Network (FFNN) is used to classify the braintissue to normal or abnormal.
The proposed automated system is tested on a data set of 572 MRI images using T1 horizontal transverse (axial) section of the brain. Hybrid method yields high sensitivity of 100%, specificity of 100% and overallaccuracy of 95.66% over FIS and FFNN. The classification result shows that the proposed hybrid techniques are robust and effective compared with other recently work.

Keywords: Brain Tumor Classification; Fuzzy Inference System; Feed Forward Neural Network; MRI .

A Robust Method for New Object Detection in Video Surveillance Systems

Dr. Ahlam Fadhil Mahmood; Loma Akram Hamdai

AL-Rafdain Engineering Journal (AREJ), Volume 22, Issue 3, Pages 213-224
DOI: 10.33899/rengj.2014.88214

Abstract
Video surveillance systems is a powerful tool for public safety and with the increasing need for more security in airports, banks, schools and other critical environments, the demand for video system is growing rapidly. Sides from the intrinsic usefulness of begin able to segment video streams into moving and background components, detecting moving blobs provide a focus of attention for recognition, classification and activity analysis, making these later processes more efficient since only “moving” pixels need to be considered. In this paper an efficient moving object detection method using modified Horprasert model for video surveillance system is present. The modified dynamic thresholds are able to detect a new object with it's shadow through different video stream in terms of light conditions. It consists of background model, distortion of brightness, color calculations and classification. Four regions are segmented depending on the thresholds foreground (moving object), background, highlight background and shadow. The proposed automatic threshold depends on background computations of brightness and is thus expected to achieved better classification performance.


Keywords: Horprasert model; background subtraction; background model; Video Surveillance.

Design of Dual Band Circular Polarization Stacked Microstrip Antenna for GPS Applications

Dr. Yessar E. Mohammed Ali; Ahmed J. Abdul Qader

AL-Rafdain Engineering Journal (AREJ), Volume 22, Issue 3, Pages 225-232
DOI: 10.33899/rengj.2014.88215

Abstract
In this paper dual-band microstrip antenna for Global Positioning System (GPS) application is designed.This design contents on two circular patch ( upper circular patch, lower circular patch) printed on a two-layer substrate of an FR4 dielectric layer, and cutting a crossed-slot in the upper patch and four I slots in the lower patch.The antenna can work at GPS Ll band (1.575GHz) and L2 band (1.227GHz).The design achieved an approximately impedance bandwidth of 15.8 MHz for L1 for two ports, while L2 band is 11.8 MHz for two ports with maximum gain of 2.54dBi and 1.177dBi in the L1 and L2 band respectively for two ports.The resulting circular polarization (with axial ratio ≤ 3 dB) has been found to meet that required for this application.The VSWR is approximately1.1 (VSWR ≤ 2) for L1 and 1.2 for L2.Results were obtained above using the software CST, which shows that this antenna can meet the demands of the signals of satellite navigation system.The antenna dimensionsare (70*70 mm2). The structure is compact and has a good application prospect. The results with low-profile characteristics make the antenna suitable for GPS applications.

Keywords: microstrip antenna, GPS antenna, Circular polarization, dual-band antenna, Global Positioning System.

The Dynamic Behavior of Different Hollow Flexible Robot’s Arms

Dr. Saad Zaghlul Saeed; Bakr Noori Alhasan

AL-Rafdain Engineering Journal (AREJ), Volume 22, Issue 3, Pages 233-241
DOI: 10.33899/rengj.2014.88216

Abstract
In this paper, four different shapes of robots' hollow arm are suggested so as to inves-tigate the effect of shape on the dynamic behavior of the arm. The finite element method is used to determine the strength of the arms and their equations of motion. The static deflection, stress and moment of inertia are calculated and compared as well as the an-gular displacement and tip vibration of the four different shapes.
A PD controller with fuzzy logic is used for tracing the desired trajectory and reduc-ing the overshoot of the system. All simulations were presented using MATLAB and SIMULINK on the arms under the same desired step trajectory for a time of two seconds. The preferred robot arm is the one that has less vibration in trajectory and after reaching the target. As a result, the tapered arm (shape B) shows better characteristics in which less deflection, stress and tracking.

Key Words: Robot arm, Finite element, Flexible link, Fuzzy controller.