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Article
Influence of Concrete Strength on the Cycle Performance of Composite Steel Plate Shear Walls

Authors: Amer M. Ibrahim عامر محمد ابراهيم --- Huda M. Najem
Journal: DIYALA JOURNAL OF ENGINEERING SCIENCES مجلة ديالى للعلوم الهندسية ISSN: 19998716/26166909 Year: 2018 Volume: 11 Issue: 4 Pages: 1-7
Publisher: Diyala University جامعة ديالى

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Abstract

The goal behind this research is to highlight on structural system using composite steel plate shear wall, this approach is widely used in many countries, due to its desired features. Composite steel plate shear wall are often considered essential in design of building to resist seismic action. This paper discuss the effect of concrete strength on behavior of CSPW, for this objective one story one bay model with different compressive strength (25, 28 , 45, 50, 55, 65)MPa ,this model formed by finite element code which is advanced by university of Amirkabir. The accuracy of the representation of the model by numerical analysis, numerical result contrast with valid experiment which explain suitable agreement. Result show increasing the compressive strength would advance the cycle behavior. By contrast the result in elastic region, it was seen initial stiffness is not enhance by varying the compressive strength.


Article
Nonlinear Dynamics of Thick Composite Laminated Plates Including the Effect of Transverse Shear and Rotary Inertia

Author: Muhsin J. Jweeg
Journal: AL-NAHRAIN JOURNAL FOR ENGINEERING SCIENCES مجلة النهرين للعلوم الهندسية ISSN: 25219154 / eISSN 25219162 Year: 2008 Volume: 11 Issue: 2 Pages: 251-262
Publisher: Al-Nahrain University جامعة النهرين

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Abstract

In this work, a suggested analytical solution for nonlinear dynamic analysis of (fiber-reinforced) composite laminated thick plate is developed by using first-order shear deformation theory (FSDT).A computer program was built for this purpose for anti-symmetric cross-ply and angle-ply, simply supported thick laminated plate and the developed equations are solved by using (MATLAB V.7) program. The finite-element solution is also adopted using (ANSYS V.8) package, to confirm the analytical results. The results presented show the effect of plate thickness-to-side ratio (h/a), aspect ratio (a/b), number of layers (N), the degree of orthotropic ratio (E1/E2), fiber orientation, boundary conditions, lamination scheme, and the effect of shear deformation and rotary inertia on the thick laminated plate

في هذه البحث تم اقتراح تحليل رياضي للتصرف اللاخطي الحركي (الديناميكي) للصفائح السميكة المركبة المقواة بالليف والمصنوعة على شكل طبقات باستخدام نظريات الطبقة المفردة "Single Layer Theories" (FSDT)تم بناء برنامج صمم لهذا الغرض، للصفائح غير المتناظرة والمثبتة (Simply Supported) تحل معادلاته باستخدام برنامج (MATLAB V.7) ولدعم وإسناد النتائج التحليلية تم وضع الحل العددي باستخدام طريقة العناصر المحددة (FEM) وباستخدام برنامج (ANSYS V.8).تمت دراسة تأثير نسبة الطول إلى السمك ((h/a)، نسبة الباع (a/b)، نسبة درجة الارثوتروبية (E1/E2، زاوية التركيب (Lamination Angle) وحالة التثبيت للصفيحة وكذلك تأثير تشوه القص والقصور الذاتي الدوار للصفائح السميكة

Keywords

: Composite --- Plate --- Shear --- Inertia


Article
Shear bond strength of posterior comp-osite cores

Authors: Jabbar H Kamel --- Abdul–Adheem R Al–Mallah --- Ahmed H Kharoufa
Journal: Al-Rafidain Dental Journal مجلة الرافدين لطب الأسنان ISSN: 18121217 Year: 2005 Volume: 5 Issue: 5 Pages: 69-74
Publisher: Mosul University جامعة الموصل

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Abstract

This study was designed to evaluate the shear bond strength(SBS) of posterior composite resin cores to tooth surface usingtwo dental adhesives and two retentive means.Thirty extracted permanent molars were used for this purpose.They were made flat by removing the occlusal one thirdusing “stone grinding wheal”. Teeth were then randomly dividedinto six groups:Groups I and IV: Scotchbond Multipurpose Plus (SbMP)and All bond 2 dental adhesives were used for groups I and IVrespectively to adhere composite to the flat tooth surface with noretentive mean as the control group.Groups II and V: A circumferential slot was prepared andcomposite attached to the tooth using SbMP and All bond 2 forgroups II and V respectively.Groups III and VI: Four self threading pins were placedand composite adhered using SbMP and All bond 2 for groups IIIand VI respectively.After storage and thermal cycling, the SBS for each groupwas measured using “universal testing machine”.The results varied according to the retentive mean and dentaladhesive used. Groups with four pins produced the highest SBSand groups with no retentive mean showed the lowest SBS. Alsothe groups using All bond 2 adhesive generally had higher valueswhen compared with the same groups using SbMP dental adhesive.Within the limits of this study, it is indicated that when thehighest SBS is to be achieved, then All bond 2 dental adhesivewith pins should be used.


Article
The shear bond strength of an immediate and delay repaired light-cure composite restoration (In vitro study)

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Abstract

Background: Defects in composite resin restoration whether discovered at the time of placement or associated withold composite resin restoration could be repaired without replacing the entire restoration. This in vitro study wasconducted to determine and compare the shear bond strength of an immediate and delay repaired light curedcomposite restoration.Materials and methods: Eighty acrylic blocks (25x25x15 mm) were constructed from cold cure acrylic resin; each onecontained an acrylic hole (6mm diameter and 3mm depth) that filled with Helioprogress composite resin. The surfacelayer of the composite resin samples was light cured through plastic strip, abraded by finishing discs and rinsed withdeionized distilled water for 15 sec. The eighty specimens were divided randomly into two groups according to thestorage time in deionized distilled water before the repair:Group I: Stored for 15 min. (Immediate repair group)Group II: Stored for 1week. (Delay repair group)Both groups were subdivided into 4 subgroups according to the surface treatment they received:Subgroup 1: No surface treatment (control)Subgroup 2: 37% phosphoric acid etchant (15 sec.)Subgroup 3: Heliobond (light activated for 20 sec.)Subgroup 4: 37% phosphoric acid and Heliobond.Repair was done by using a standardized translucent plastic straw (3mm diameter and 6mm length) and was filledHelioprogress composite resin and light cured for 40 sec. in four directions. All the specimens were stored in deionizeddistilled water for 24 hr. testing was done by the Zwick testing machine by applying shearing force with speciallydesigned chisel-shape rod. Data obtained were statistically analyzed using analysis of variance test and t-test.Results: The results showed very highly significant difference between the similar subgroups in group I vs. group II andthere was non-significant difference between subgroup 1 vs. 2 and between subgroup 3 vs. 4.Conclusion: Delaying the repair procedure for 1 w resulted markedly reduced the bond strength, the surfacetreatment with 37% phosphoric acid slightly reduced the bond strength in the immediate repair while slightlyincreased it in the delay repair, Furthermore, the surface treatment with Heliobond fifth generation bonding agentmarkedly increased the bond strength in both repairs.

Keywords

Repair --- composite --- shear bond


Article
The Effect of Different Disinfectant Solutions on Shear Bond Strength of Acrylic Teeth to Flexible Denture Base Material

Author: Ihssan F Al-Takai
Journal: Al-Rafidain Dental Journal مجلة الرافدين لطب الأسنان ISSN: 18121217 Year: 2014 Volume: 14 Issue: 24 Pages: 145-152
Publisher: Mosul University جامعة الموصل

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Abstract

is to evaluate the effect of three different disinfectant solutions on shear bond strength of artificial acrylic teeth for retention to flexible denture base material at three different periods of time. Materials and Methods: The total number of samples was (60) divided into 4 groups according to the three chemical disinfectant solution which used and the control distilled water group: Group( I) vinegar group, Group( II) salt group , Group(III) Chlorohexidine group , Group (IV ) the control distilled water group, where each group was subdivided into three subgroups according to disinfection periods which are 1week, 1month and 3month where each group contain five samples. The samples of shear bond strength test were consist of acrylic teeth with T-shape design for retention attached to rod of valplast The test was performed using a Universal testing machine. ANOVA, DuncunP,Ps multiple range and Post Hoc Tests were carried out to determine the significant difference at p ≤ 0.01%. Results: The results appeared that control distilled water group has the highest value for the three periods of disinfection (1 week,1month,3months), while vinegar solution group has the least value. The results showed that there were significant differences between the four tested groups and also there were significant differences among all periods of time of disinfections. Conclusion: There was a significant difference of shear bond strength between artificial teeth and flexible denture base material after disinfection in the four disinfectant solutions for all periods of time of immersion. Vinegar group had highest effect on the bond strength while the distilled water group had the least effect after all periods of time of disinfections. Shear bond strength decreased with increasing the time immersion. The shear bond strength was lowest in chloherxidine group as the time of immersion increase when compared with the two other groups of disinfection solutions in this study.


Article
Analysis of Continuous Composite Concrete - Steel Girders with Partial Interaction

Authors: Mohannad H. Al-Sherrawi --- Qusay Asa'ad Al-Aquly --- Husain M. Husain
Journal: Journal of Engineering مجلة الهندسة ISSN: 17264073 25203339 Year: 2006 Volume: 12 Issue: 3 Pages: 802-820
Publisher: Baghdad University جامعة بغداد

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Abstract

In the present study, a general nonlinear one-dimensional finite element beam model is developed for the analysis of composite beams. The proposed model is based on the partial interaction theory of composite beams where the flexibility of shear connectors is allowed. By using a layered approach for the composite beam cross-section and including the material nonlinear behavior of concrete, steel, shear connector and reinforcing steel, the proposed method of analysis is capable of predicting the response of composite beams throughout the elastic, inelastic and ultimate load ranges in one complete analysis.Numerical case studies are presented to demonstrate the validity and applicability of the present method. The results are compared with experimental and analytical or numerical results obtained by other investigators. Also the results are compared with ANSYS package results. The maximum differences in deflection and slip for the examples considered are 12% and 14% respectively when compared with ANSYS and 5% and 11% when compared with experimental work. Accordingly, the proposed nonlinear finite element model represents an efficient and simple tool for the full range analysis of composite beams.

في هذه الدراسة تم عرض نموذج عام لا خطي ذي بعد واحد بطريقة العناصر المحددة لدراسة العتبات المركبة. والنموذج المقترح مبني على أساس نظرية الربط الجزئي للعتبات المركبة إذ أن مرونة روابط القص شئ مسموح به. إن الطريقة المقترحة قادرة على أن تعطي تصوراً واضحاً عن تصرف العتبات المركبة خلال التحمل الخطي واللاخطي والحمل الأعظم في تحليل واحد وذلك باستعمال طريقة تجزئة المقطع للعتبة إلى طبقات بالإضافة إلى التصرف اللاخطي لمادة الخرسانة والحديد وروابط القص وحديد التسليح.ولاختبار صحة ودقة الطريقة المقترحة، تم تطبيقها على دراسات سابقة حيث تمت المقارنة مع النتائج التجريبية والتحليلية المستخلصة من قبل باحثين سابقين و كذلك تمت المقارنة مع البرنامج الجاهز ANSYS . إن القيم العظمى للفرو قات في الهطول و الانزلاق للأمثلة التي تم اعتمادها في هذه الدراسة كانت 12% و 14% على التوالي عند مقارنتها مع برنامج (ANSYS) و5% و 11% عند مقارنتها مع الفحوصات العملية. وبناء على ما تقدم، فإن النموذج المقترح نموذج فعال كما أنه بسيط للتحليل الكامل للعتبات المركبة ويمكن استعماله للتصميم والتحليل الاعتياديين.


Article
Shear bond and rebond strengths of four composite systems

Authors: Hussain A Obaidi (BDS, MSc ** ) د. حسين العبيدي --- Raid Kh Mustafa BDS, MSc د.رائد مصطفى
Journal: MUSTANSIRIA DENTAL JOURNAL مجلة المستنصرية لطب الاسنان ISSN: 18138500 Year: 2005 Volume: 2 Issue: 2 Pages: 235-243
Publisher: Al-Mustansyriah University الجامعة المستنصرية

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Abstract

:The orthodontic composite bonding material is available in various systemwhich are chemically—cured composite such as Two—past and No—mix systems in whiclthe composite set by chemical reaction; Light—cured composite system, in whicl:composite set by light exposure; and Dual—cured composite system, by which thcomposite cured by chemical reaction and light exposure. Thus it is necessary tt.investigate and compare the commonly used composite bonding systemsThis study was aimed to determine and compare the shear bond and reboncstrength of: Two—past composite system (Concise, 3M, Unitek USA), No—mix composite,system (Right—On, TP Orthodontics UK), Light—cured composite system (Transbond XT.)M Unitek USA), and Dual—cured composite system (Sono—Cem ESPE, Germany3,Fifty six upper premolars were divided into four groups of fourteen, each groupmesh—backed metal advant edge brackets were bonded to the buccal surface ofthe teethusing one of the composite system according to the instruction of manufacturer. Then.bonded samples were thermocycled in an attempt to simulate oral circumstancesThe samples were subjected to shear force using the universal compressionmachine apparatus, then the results were recorded in Megapascal (Mpa). The remainingcomposite on the buccal surface of the tooth was removed by hand sealer and polished, anew bracket was bonded to the buccal surface of the tooth using the same type ofcomposite system. The rebonded samples were tested under shear strength using the.universal compression machine apparatus and the results were again recorded in Mpa,The data were statistically analyzed using descriptive analysis, ANOVA test.Dtu1can’s Multiple Range Test and Student’s t—test at p g 0.0lThe results showed that the Concise had no significant higher bond shear strengththan the Transbond and Sono—Cem composite systems, and there was signilicant increasebond strength of the Concise than the Right—On composite systems. Furthermore, therewere no significant differences in bond shear strength among the Right—On, Transbond.and Sono—Cem composite systemsThe shear rebond strength of composite systems was decreased, and there were The shear rebond strength of composite systems was decreased, and there were no.significant differences in bond and rebond shear strength of each composite systemConclusions of this study are that Concise has the higher shear bond strength but.has highest regression in its rebond shear strength


Article
Improving Shear Strength of Soft Clay by Using Torn Belts Chips
تحسين مقاومة القص للتربة الطينية الضعيفة باستخدام رقائق الاحزمة الممزقة

Author: Haider Mohammed Mekkiyah حيدر محمد مكية
Journal: Al-Khwarizmi Engineering Journal مجلة الخوارزمي الهندسية ISSN: 18181171 23120789 Year: 2016 Volume: 12 Issue: 1 Pages: 117-129
Publisher: Baghdad University جامعة بغداد

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Abstract

Random throwing of industrial waste has a significant impact on the environment unless it takes into account the conditions of engineered destroying and/or re-used. Taking the advantage of re-using waste materials in engineering projects represents a well-planned project in order to resolve a lot of engineering problems for some difficult soils. The objective of this study was to evaluate the capability and effects of Rubber Shreds (RS) from scrap torn belts towards improving the shear strength of soft clay. A direct shear tests were conducted on soft clay-RS mixture. The following parameters were investigated to study the influence of RS content, water content, normal stress, and dilation ratio. From experimental test results it was found that previous parameters affecting the shear strength of soft clay. Increasing RS content was found effective in improving the shear strength of soft clay when the normal stress increases provided that fixed water content used in the mixture. Cohesion, c and angle of friction,  were increased by ratio of (1.4-2.3) and (1.5-2) respectively. However, it was revealed that RS content mustn’t exceed the liquid limit level of soft soil. If the water content increases and exceeding the liquid limit level of soft clay, shear strength, cohesion and angle of friction will begin to decrease by reduction percentage of (15%-55%) and (20%-45%) respectively in spite of 30% rubber inclusion. The dilation ratio was highly affected by water content increment; disturbed path of dilation ratio were observed with increasing water content in soil mixture.

رمي النفايات الصناعية بشكل عشوائي له تأثير كبير على البيئة ما لم تراعى الشروط الهندسية في أتلافها. أن امكانية الافادة من هذه النفايات وأعادة استخدامها في المشاريع الهندسية يمثل تخطيطا جيدا لحل الكثير من المشكلات الهندسية التي تعاني منها بعض الترب الصعبة. الغرض من هذه الدراسة هو تقويم قابلية وتأثير أستخدام شرائح من الاحزمة الممزقة لتحسين مقاومة القص للترب الطينية الضعيفة. تم تبني فحص القص المباشر على خليط من قطع المطاط المقطعة والتربة. وقد تم دراسة العوامل التالية: نسبة القطع المطاطية، محتوى الماء، مقدار الاجهاد العمودي المسلط، وكذلك (Dilation Ratio). لوحظ من خلال النتائج العملية أن العوامل أعلاه تؤثر على مقاومة القص للتربة. زيادة محتوى RS سببت تحسين مقاومة القص للتربة الطينية مع زيادة الاجهاد العمودي ومن خلال محتوى مائي ثابت. لوحظ أن التماسك وزوايا الاحتكاك الداخلي ازدادتا أيضا بشرط عدم تجاوز نسبة RS عن حد السيولة للتربة الطينية الضعيفة. أن هذه العوامل تتأثر بشكل كبير في حال زيادة محتوى الماء عن محتوى حد السيولة حيث لوحظ نقصان كل من التماسك وزواية الاحتكاك الداخلي. نسبة (Dilation Ratio) تأثرت كثيرا بزيادة نسبة الماء فلوحظ تشوه مسار (Dilation Ratio) بزيادة نسبة الماء في خليط التربة.


Article
Mathematical extraction equation of horizontal shear transfer in interface between two concrete members

Author: Hakim S. M. Al-Kurayshi
Journal: Al-Qadisiyah Journal for Engineering Sciences مجلة القادسية للعلوم الهندسية ISSN: 19984456 Year: 2016 Volume: 9 Issue: 1 Pages: 106-118
Publisher: Al-Qadisiyah University جامعة القادسية

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Abstract

Shear is transferred through interface between two concrete members by two mechanisms either by aggregate interlock or by dowel action or by both in the same time. This media is very complex and there are so many variables affecting shear transfer like surface shape and final treatment of the concrete surfaces. Histories of the previous researchers are mentioned in this paper to find out the applicable results of their equations. It is noticed that most of them depend on only clamping stress due to dowel action while others used besides that the type of concrete used namely its compressive strength. A mathematical statistical trials are made in this paper to find out the most accurate and suitable equation which simulates the action happened in this media. An equation of six parameter polynomial is obtained containing clamping stress and compressive strength of concrete. Assumed values of the mentioned variables are used in this equation to find out the horizontal shear strength. The deviation recorded is about 4% which is an acceptable one.


Article
Effect of Shear Span-Depth Ratio on Shear Strength of Porcelanite Lightweight Aggregate Reinforced Concrete Deep Beams Strengthened by Externally Bonded CFRP Strips

Authors: K.F. Sarsam --- N.A.M. Al-Bayati --- A.S. Mohammed
Journal: Engineering and Technology Journal مجلة الهندسة والتكنولوجيا ISSN: 16816900 24120758 Year: 2017 Volume: 35 Issue: 3 Part (A) Engineering Pages: 267-275
Publisher: University of Technology الجامعة التكنولوجية

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Abstract

This paper presents an experimental investigation of structural behaviour of reinforced concrete deep beams strengthened in shear by CFRP strips. The experimental program consisted of fabricating, casting and testing of nine identical porcelainte lightweight aggregate reinforced concrete deep beams. Three of the tested deep beams were unstrenghtened to serve as reference beams, while the remaining beams were tested after being strengthened using CFRP strips in two different orientations (vertical and horizontal). The locally available natural porcelanite aggregate is used to produce lightweight aggregate concrete. The beams were designed to satisfy the requirements of ACI 318M- 14 building code. In order to insure shear failure modes, adequate flexural steel reinforcement were provided. Effect of three different values of shear span to effective depth ratio (a/d =1.0, 0.8, 1.2) were selected. All beams have been tested as a simply supported beams subjected to two concentrated points loading. The beam specimens were tested up to failure under monotonic loads. The experimental work showed that the failure load increases as the shear span to effective depth ratio deceases. As the shear span to effective depth ratio decreased from 1.0 to 0.8, the percentage of increase in the ultimate load was about 24%. In addition, the diagonal compression strut crack of unstrenghtened control beams was changed to several diagonal cracks at mid depth within the shear span of the strengthened beams and exhibited more ductile failure mode.

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