research centers


Search results: Found 88

Listing 1 - 10 of 88 << page
of 9
>>
Sort by

Article
Effect Of Reinforcement Ratio On Punching Shear Strength Of Reactive Powder Concrete Slab Reinforced With CFRP Bars
تاثير نسبة التسليح على مقاومة القص الثاقب لسقوف المساحيق الفعاله المسلحه بواسطة قضبان الياف الكاربون البوليمريه

Authors: Abdul Muttalib I. Said --- Samir M. Chasib
Journal: Misan Journal of Acodemic Studies مجلة ميسان للدراسات الاكاديمية ISSN: 1994697X Year: 2017 Volume: 16 Issue: 32 Pages: 1-15
Publisher: Misan University جامعة ميسان

Loading...
Loading...
Abstract

This work is devoted to study the effect of reinforcement ratio (ρ) on punching shear strength of reactive powder concrete slab reinforced with CFRP bars. The experimental program includes investigating the effect reinforcement ratio (ρ) on the first crack, type of failure, load – deflection curve and compression the ultimate punching shear capacity with ACI – 440 equation. All tested slabs were with dimension (1150 × 1150) mm and tested under concentrated load on column at the center of the slab.

يهتن البحث الحالي بدراسة تاثير نسبة التسليح على هقاوهة القص الثاقب لسقىف الوساحيق الفعاله الوسلحه بىاسطة قضبباى اليبافالكاربىى البىليوريه. يتركب البرنباها العولبي حبىت استقتباي تباثير نسببة التسبليح علبى اوت بق نبىع الفشب, هحححبي لالحوب, –الهطببىت و هقارنببة اعلببى قيوببه لوقاوهببة القببص هببي هعا لببه الكببى ا هريكببي ل ACI-440 . كبب, الحوببافح الوفحىعببه بابعببا5511 هلن وفحتت تحت حو, هرك على الكىلىم بالوحتتف. × ل 5511


Article
Evaluation of Some Mechanical Properties of Reinforced Acrylic Resin Denture Base Material(An In Vitro Study)

Authors: Luma M Al–Nema --- Tarik Kassab Bashi
Journal: Al-Rafidain Dental Journal مجلة الرافدين لطب الأسنان ISSN: 18121217 Year: 2009 Volume: 9 Issue: 13 Pages: 57-65
Publisher: Mosul University جامعة الموصل

Loading...
Loading...
Abstract

Aims: To evaluate the effect of thickness of acrylic denture base resin on the transverse strength, also to evaluate the effect of metal and fiber reinforcements on the fracture resistance of denture base resinby four mechanical tests: Transverse strength; Charpy impact strength; Tensile strength and Rockwell Indentation Hardness. Materials and methods : Heat–cured resin, and three types of reinforcing metalswere used which were: The cobalt–chromium alloy mesh, stainless steel wire and nickel alloy plate.Three forms of glass fiber also were used: Random, woven, and aligned unidirectional. The effect of these reinforcing materials on the mechanical properties of heat–cured resin had been evaluated bymeasuring the transverse strength by the Instron testing machine, tensile strength by the Textile tensile strength Tester, the impact strength by the Charpy type impact Tester and finally the hardness by the Rockwell hardness tester. Three hundred samples were prepared in this study. Results: Revealed a statistically significant effect of thickness on the transverse strength of heat–cured resin. Results alsoshowed that all forms of fiber and metal reinforcements had a significant effect on the transverse strength, tensile strength , impact strength and hardness of denture base resin. Conclusions: The thickness significantly increased the transverse strength of denture base resin. All forms of metal and glass fiber reinforcement significantly improved the transverse strength, impact strength and tensile strength of denture base resin. All forms of metal and fiber reinforcement acted to reduce the hardness of denture base resin


Article
Evaluation Mechanical Properties of Polymer Composites Reinforced by different Metal Powders
تخمين الخواص الميكانيكية للمتراكبات بوليمريه المقواة بمساحيق معدنية مختلفة

Authors: Sihama Issa Salih --- Safaa Nayyef --- Alyaa H .Abd Alsalam --- Ammar Mousa Hasan
Journal: Engineering and Technology Journal مجلة الهندسة والتكنولوجيا ISSN: 16816900 24120758 Year: 2015 Volume: 33 Issue: 7 Part (B) Scientific Pages: 1348-1360
Publisher: University of Technology الجامعة التكنولوجية

Loading...
Loading...
Abstract

This research covers reinforcement of unsaturated polyester resin by metal powders, and studying some of their mechanical properties. The samples were prepared by hand lay-out technique. The unsaturated polyester resin was reinforced by two types of metal powders Copper (15.598 µm) and aluminum (21.533µm) at selected volume fraction of (0, 5, 10. 15, 20 and 25 %). The study of mechanical properties includes tensile properties (strength at fracture point, elastic modulus and elongation at at break), flexural strength and flexural modulus, impact properties and hardness. The results show a noticeable increase in values of tensile strength at fracture point and tensile modules of elasticity, as the volume fraction of metal powder increase and reach to maximum value at 15 % volume ratio for both types, where as flexural strength, flexural modulus and fracture toughness reach to maximum value at 10 %volume ratio for both types composites, however elongation at break shows decrement as the volume fraction of metal powder is increased for both types composites.

يتضمن هذا البحث تقوية راتنجات البوليستر غير المشبعة بمساحيق معدنيه، ودراسة بعض خصائصها الميكانيكية. تم إعداد العينات بالتقنية اليدوية. وقد تمت تقوية البوليستر غير المشبع بواسطة مجموعتين من مساحيق المعدنيه (النحاس و آلالمنيوم) 15.598 )،21.533 مايكرون (على التوالي. بكسور حجميه مختاره (0، 5، 10 ،15 ، 20 and 25%) وتشتمل دراسة الخواص الميكانيكية خصائص الشد (الاجهاد عند نقطة الانهيار، ومعامل مرونة والمطيلية) واجهاد الانحناء ومعامل مرونة الانحناء ، وخصائص الصدمة والصلادة. أظهرت النتائج زيادة ملحوظة في قيم إجهاد الشد عند نقطة الكسر ومعامل المرونة بزيادة الكسر الحجمي للمساحيق المعدنيه ووصلت إلى أقصى قيمة عند النسبة 15% لكلتا المجموعتين. بينما قيم مقاومة الانثناء ومعامل الانثناء ومتانة الكسر ووصلت إلى أقصى قيمها عند النسبة %10 لكلتا المجموعتين. في حين أنخفضت قيم المطيليه عند نقطة الكسر بزيادة الكسر الحجمي للمساحيق المعدنيه ولكلتا المجموعتين.


Article
Evaluation of Impact and Transverse Strength of Denture Bases Repaired with Nano Reinforced Resin

Loading...
Loading...
Abstract

Background: Failure of resin bases were a major disadvantage recorded in the constructed dentures. Reinforcements of the repair joint with nano fillers represent an attempt to enhance the strength and durability. The purpose of the research was to estimate the influence of nano fillers reinforcement with (ZrO2 and Al2O3) on impact and transverse strength of denture bases repaired with either cold or hot processing acrylic resin.Materials and methods: A hundred and forty (140) samples were processed with hot cured resin and organized in subgroups depending on the repair materials and condition (without repair (control), repair with hot cure, cold cure, hot and cold cure reinforced with either (5% Zr2O or 0.5% Al2O3). The samples in these subgroups were processed depending on the test applied (impact and transverse strength). The samples were immersed in distalled water for about four weeks at 37°C before testing, after that, the samples prepared for each test were subdivided depending on the selected subgroups of the study. Repairing the samples with cold cure resin was done with the aid of Ivomet; after that the samples incubated for 48 hours in 37°C distilled water. Transverse strength test was done by using INSTRON universal testing machine while the impact test was done by using CHARPY impact testing machine.Results: The reinforcement of the repair joint with nano-fillers improves both impact and transverse strengths.Conclusion: Repair strength is directly proportional to the mode of resin processing, reinforcement with nano-fillers improve the strength of the repaired joint significantly


Article
Evaluation of some physical properties of the copolymerized temporary crown and bridge auto–cured acrylic resin (Reinforcement)

Authors: Akram A Mohammad --- Nadiaa H Hasan --- Lamia T Rejab
Journal: Al-Rafidain Dental Journal مجلة الرافدين لطب الأسنان ISSN: 18121217 Year: 2007 Volume: 7 Issue: 10 Pages: 160-165
Publisher: Mosul University جامعة الموصل

Loading...
Loading...
Abstract

Aims: To evaluate some of the physical properties which are transverse strength, tensile strength,surface hardness, water sorption and solubility of the auto–cured acrylic resin when copolymerizedwith epoxy resin at two different ratios 10% and 20% of its weight and then compared with that ofauto–cured alone and heat–cured acrylic resin alone. materials and methods: The tested samples weredivided into four groups according to the materials to be used and the samples of each group weresubdivided according to the test to be done. The samples were prepared according to ADASpecification No. 12. Statistically analysis of the physical properties was with (ANOVA) and Duncan'smultiple range test to determine significant different at (p ≤ 0.05 ) level of significance, and the meanvalue of the water sorption and solubility ratios compared with accepted limit of ADA SpecificationNo. 12. Results: The transverse strength, tensile strength and surface hardness in this study showed thatthere was a highly significant difference between the four tested groups. The result appeared improvingof the mechanical properties and decreasing the ratio of water sorption and solubility of the auto–curedacrylic resin and the resin was reinforced when copolymerized at 10%, but the values still not reachedthat of the heat–cured acrylic resin and they became worse when copolymerized at 20%.


Article
An Approach In Improving The Properties Of Sand Dunes

Author: Saad F.I. AL-Abdullah
Journal: Journal of Engineering مجلة الهندسة ISSN: 17264073 25203339 Year: 2006 Volume: 12 Issue: 4 Pages: 930-939
Publisher: Baghdad University جامعة بغداد

Loading...
Loading...
Abstract

An experimental study to improve sand dunes to gain economic construction ofhighway using these locally available materials. The study was divided into two approaches;the first was by using different bituminous binder proportions from (2) to (10) percent, whilethe second was to use fine metals as reinforcement. The results show an increase in the degreeof improvement as reinforcement layers and silt contents were increased. Also it was foundthat 8% 0f asphalt cement increase the stabilization of sand dunes.

أجريت دراســات مختبرية لتحسين الكثبان الرملية للحصول على مادة إنشائية اقتصاديةلاستعماها كمادة انشلئية محلية في أعمـــال الطرق .قسمت الدراسة إلى اتجاهين الأول باستعمال المحتوى الإسفلتي بنسب من (2)% إلى( 10)%بينما الاتجاه الثاني باستعمال شبكات التسليحتبين من النتائج إن هناك زيادة في درجة التحسين كلما زادت طبقات التسليح مع زيادة نسب الغرين.كذلك وجد أن النسبة 8%من الإسفلت الأسمنتي قد سببت زيادة في تثبيت الكثبان الرملية.

Keywords

Sand Dunes --- Local --- Reinforcement --- Asphalt --- Triaxial


Article
Effect of Fiber Orientation on the Root Stresses of the Gear Tooth

Authors: Issam Shamouael --- Mohammad Q. Abdullah
Journal: Journal of Engineering مجلة الهندسة ISSN: 17264073 25203339 Year: 2005 Volume: 11 Issue: 2 Pages: 307-326
Publisher: Baghdad University جامعة بغداد

Loading...
Loading...
Abstract

The effect of fiber orientation angle of composite materials on the gear tooth root stresses is analytically investigated in the order to select the required orientation of the fibers inside the gear tooth, which leads to improve the gear tooth strength. The effect of geometrical parameters (loaded or unloaded pressure angles, number of teeth, radius of fillet and profile correction) and type of fibers (glass, graphite and boron) are also studied. A stress analysis using the finite element method is performed for reinforced gear subject to bending loads. The results indicate that there is an effect of the fiber orientation on the root stresses of the gear tooth, and also there is a direct proportionality between the improving of the gear strength with geometrical parameters.

في هذا البحث تم دراسة تأثير توجه الالياف للمواد المركبة على اجهادات الجذر لاسنان التروس لغرض اختيار الزواية المطلوبة للالياف داخل اسنان التروس والتي تؤدي الى تحسين مقاومة الاسنان للأحمال. وتم ايضا دراسة تأثير الابعاد الهندسية التصميمية ) Geometrical Parametersزاوية الضغط المحملة والغير محملة، عدد أسنان الترس، نصف قطر المتكأ الزاوي ومعامل التصحيح) وكذلك تأثير نوع الاألياف المستخدمة (زجاج، جرافيت، بورون). وقد تم اجراء التحليل العددي باستخدام طريقة العناصر المحددة للحصول على توزيع الاجهادات داخل أسنان التروس. وقد اتضح من النتائج المستحصلة بان اتجاه الالياف يؤثر على اجهادات الجذر لاسنان التروس، وكذلك اتضح من النتائج بأن هناك علاقة مباشرة بين اجهادات الجذر مع الابعاد الهندسية التصميمية.


Article
Pullout Strength of Headed Deformed Reinforcement Embedded in Fibrous Concrete
مقاومة الأقتلاع لحديد التسليح المدعم برأس مطمور في خرسانة ليفية

Authors: Samir Sami Majeed سامر سامي مجيد --- Prof. Dr. Saad Ali AlTaan أ.د. سعد علي الطعان
Journal: AL Rafdain Engineering Journal مجلة هندسة الرافدين ISSN: 18130526 Year: 2010 Volume: 18 Issue: 1 Pages: 1-12
Publisher: Mosul University جامعة الموصل

Loading...
Loading...
Abstract

This research contains a study of the effect of connecting square steel pieces (10mm) thick with dimensions (20×20,25×25,30×30mm) by welding with the ends of reinforced steel bars with diameters (10,12,16mm) embedded in fibrous concrete with a percentage volume of steel fibers (0.0,0.4,0.8,1.2%) over the development length required to reach steel reinforcement to yield strength ( )in case of straight reinforcement steel bars with the same diameters without steel headed.Keywords: fibrous concrete; anchors; headed reinforcement

الخلاصةيتضمن هذا البحث دراسة تأثير ربط قطع حديدية مربعة الشكل بسمك (10mm) وأبعاد (20×20,25×25,30×30mm) بواسطة اللحام بنهايات قضبان حديد تسليح بأقطار (10,12,16mm) مطمورة في خرسانة ليفية بنسب إضافة حجمية للألياف الفولاذية (0.0,0.4,0.8,1.2%) على طول التثبيت المطلوب توفيره لأيصال حديد التسليح إلى إجهاد الخضوع ( ) في حالة قضبان حديد تسليح ممتدة مستقيمة بنفس الاقطارغير مدعمة برؤوس حديدية.


Article
Non-Destructive Test of Concrete Structures Using: FERROSCAN

Author: Aseel A.Salman
Journal: Engineering and Technology Journal مجلة الهندسة والتكنولوجيا ISSN: 16816900 24120758 Year: 2011 Volume: 29 Issue: 14 Pages: 2933-2941
Publisher: University of Technology الجامعة التكنولوجية

Loading...
Loading...
Abstract

The non-destructive testing (NDT) industry is reviewed, the major techniques being described and current development directions and challenges identified. One of the most common techniques (ferroscan) is explained briefly below. Ferroscan is a non-destructive measuring method based on the generation and detection of electromagnetic fields in conductive materials. In concrete structures, the strength of this induced field depends on the diameter and the cover of thereinforcement. The techniques has been shown to find location and orientation of reinforcement bars, stirrup, or other metal pipe, in the concrete, measure thickness of concrete cover over reinforcement bar, and to determine the bar diameter. In this paper Ferroscan FS 10, a portable detection, was used for measuring and mapping system which provides an immediate liquid crystal image of the reinforcement within a survey area which include reinforcement concrete beam(1000*200*120)mm. The great advantage of measurements with ferroscan, compared to existing detection systems, is that the measurements can be carried out far quicker and more accurately, accurate mapping out of reinforcement and verification of reinforcement in old building.


Article
EXPERIMENTAL STUDY OF R.C. CORNER DETAILS
دراسة عملية لتفاصيل الوصلات الخرسانية المسلحة

Loading...
Loading...
Abstract

This investigation presents an experimental study of strength and behaviour of various types of reinforcement details in concrete corner subjected to bending moment tended to open the angle. Ten specimens with various arrangements of reinforcement in the corner region are tested to study the effect of reinforcement detail, corner strength, cracks type, cracking moment, cracks pattern, corner deflection and corner efficiency. The specimens are designed to represent an actual prototype of a portal frame corner. The compressive strength of concrete in the test varies from (37.1) to (43.6) MPa, and steel tension ratio in legs is constant at ρ = 0.0081 in all test specimens. The nominal dimensions of the tested corners are (1077.8 mm) in overall length, (600 mm) in height and (150mm) in thickness, the nominal width, and the effective depth for all corner's leg section is held constant at (150 mm) and (129 mm) respectively. All corners are supported to be hinged in one leg by two hooks and rolled in other leg, also all corners are loaded by steel frame where, it produces moment tends to open the angle. Concrete strains at three different loading stages are recorded for each tested corner; also load deflection curves were plotted. Throughout the test operation crack patterns were drawn and the mode of failure of the tested corners is identified, which is divided into two types (flexural and bearing) failure. It was found that reinforcement detailing in corners subjected to moment tends to open the corner has important effect on the strength and the mode of failure of the corner. Depending on the results of the current experimental work some details are recommended to be used in the field work.

يستعرض البحث الحالي دراسة عملية لمقاومة وتصرف أنواع متعددة من تفاصيل التسليح للأركان الخرسانية المعرضة لعزوم إنحناء تعمل على فتح الزاوية. تم فحص (10) نماذج لتفاصيل تسليح مختلفة في منطقة الأركان لدراسة تأثير تفاصيل التسليح، مقاومة الخرسانة، نوع التشققات، عزوم التشققات، أشكال التشققات، هطول الركن الخرساني وكفاءته. صممت النماذج لكي تمثل وتحاكي أركان الهياكل الإنشائية. مقاومة إنضغاط الخرسانة في الفحوصات تراوحت بين (37,1 و 43,6) ميكاباسكال، نسبة حديد الشد في سيقان الأركان كانت ثابتة وتساوي(ρ = 0.0081) لكل النماذج المفحوصة. أبعاد الأركان التي تم فحصها هي (1077,8ملم للطول، 600ملم للإرتفاع و 150ملم للسمك). تم الحفاظ على العرض والعمق الفعال ثابتاً لسيقان كل الأركان وبما يساوي (150ملم و 129ملم) على التوالي. أسندت جميع الأركان على شكل مفصلي في أحد السيقان بإستخدام عقفتين وأسندت الجهة الأخرى بمفصل متحرك. تم تحميل جميع الأركان بواسطة هيكل فولاذي يقوم بتوليد عزم يعمل على فتح الزاوية. تم تسجيل الإنفعالات في الخرسانة لثلاثة مراحل تحميل مختلفة ولكل ركن تم فحصه كما وتم رسم منحيات الحمل والإزاحة. أثناء عملية الفحص تم رسم التشققات الحاصلة في الركن الخرساني وتحديد نوعية الفشل الحاصلة والتي كانت على نوعين (فشل إنحناء أو إرتكاز). لقد تبين بأن تفاصيل التسليح في الأركان الخرسانية المعرضة لعزوم انحناء تعمل على فتح الزاوية لها تأثير كبير على مقاومة ونوع الفشل الحاصل في الركن الخرساني. بالإعتماد على النتائج المستحصلة من البحث الحالي تم إختيار عدد من التفاصيل والتوصية بإعتمادها في المجال الحقلي.

Listing 1 - 10 of 88 << page
of 9
>>
Sort by
Narrow your search

Resource type

article (88)


Language

English (65)

Arabic and English (12)

Arabic (6)


Year
From To Submit

2019 (2)

2018 (14)

2017 (10)

2016 (11)

2015 (9)

More...