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Lecture 4

[0  ] 8T. [0/  45/ 90] S. [  45] 2S. [90] 8T. E 1 (10 6 psi). 18- 20. 7.5. 2.9. 1.5.  1 (10 3 psi). 250. 70. 2.6. 8. ADVANCED COMPOSITES. Brain Teasers: There is one word in the English language that is always pronounced incorrectly. What is it?.

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Lecture 4

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  1. [0]8T [0/  45/ 90]S [ 45]2S [90]8T E1(106 psi) 18- 20 7.5 2.9 1.5 1(103 psi) 250 70 2.6 8 ADVANCED COMPOSITES Brain Teasers: There is one word in the English language that is always pronounced incorrectly. What is it? Tension Test on Multi Directional Laminate, material: AS1/3501-5A (gr/ep) Lecture 4

  2. وحاشيته ..!! أثناء زيارته لبريطانيا .. جورج دبليو بوش قابل الملكة البريطانية وسألها : جلالة الملكة !.. كيف تقودين حكومة ناجحة من حولك ؟؟!! هل عندك نصائح معينة أستطيع الاستفادة منها ؟؟!! حسناً, أجابت الملكة وأردفت قائلة : أهم شيء هو أن تحيط نفسك بأشخاص أذكياء من حولك !! و على الفور رد جورج دبليو بوش : ولكن !.. كيف أستطيع أن أحدد أن من حولي هم من الأذكياء ؟ تناولت الملكة كوبا من الشاي ثم قالت : أن هذا سهل للغاية فقط أسألهم لغزاً ذكياً. الملكة ضغطت على زر الأنترفون وقالت : رجاء أرسلوا لي توني بلير هنا . دخل توني بلير إلى القاعة وقال نعم صاحبة الجلالة. قالت الملكة أجب عن هذا اللغز : أبوك وأمك عندهم طفلا ليس هو أخوك ولا هو أختك فمن هذا الطفل ؟ بدون تفكير أجاب توني بلير : لابد أنه أنا قالت الملكة : نعم نعم جيد. عاد جورج دبليو بوش إلى البيت الأبيض في واشنطن سأل الرئيس بوش دك تشيني قائلاً أجب عن هذا السؤال : أبوك وأمك عندهم طفلا ليس هو أخوك ولا هو أختك فمن هذا الطفل ؟ لست متأكداً أجاب دك تشيني اسمح لي يا سيادة الرئيس بالرجوع إليك ثانية لإجابة هذا السؤال. دك تشيني سأل كل المسؤولين و لكن أحداً لم يعطه إجابة أخيراً انتهى إلى غرفة الرجال و سأل كولن باول صارخا بوجهه كولن : أبوك وأمك عندهم طفلا ليس هو أخوك ولا هو أختك فمن هذا الطفل ؟ كولن باول قال : سهل إنه أنا. ابتسم دك تشيني وقال : شكراً لك. رجع تشيني إلى مكتب الرئيس بوش وقال : سيادة الرئيس لقد قمت ببعض البحوث وأستطيع أن أجيب عن اللغز: إنه كولن باول. وقف الرئيس بوش من مكانه وصرخ في وجه تشيني بقوة وقال : لا لا لا,  إنه توني بلير يا غبي !؟؟

  3. Empirical Example of Multi Directional 0, 45, -45, 90,90,-45, 45, 0 Laminate or %(0/45/90) (25/50/25) Laminate 8 PilesσE 25% 0’s 25% of 250 Ksi = 60 4.5 50%±45’s 50% of 26 Ksi = 13 1.5 25% 90’s 25% of 8 Ksi = 40.3 77 6.3 Micro-cracks can develop in the 90 ply at low stress/strain level.

  4. Constituent Materials1. Glass/ Fiberglass: • Characteristics: • High tensile strength • Elastic • Use to 750-1000 F • Good dimensional stability • Corrosion resistant • Excellent Electrical Props. • Low- cost • Because of low E, it don’t rate as an advanced composite. • Produced by extrusion of drawn molten glass. • Textile fibers account 27% of all glass produced. • Two forms are important: Continuous and discontinuous

  5. Glass/ Fiberglass (Cont.) Silica sand, Limestone, Boric acid and others mixed and melted in furnace (2300 F). Three types are important: 1- Direct melt process: molten glass flows directly to fiber. 2- Marble process: molten glass flows to marble making machine. 3- Sol-gel process

  6. Glass/Fiberglass (Cont.) Roving: Several strands of filaments wound together. Roving is the main product form for applications such as FILAMENT WINDING Sizing: Chemical coating that protects fiber from damage. E-glass: (Aluminoborosilicate) (E is for electrical) is the most commonly used gl- draws well, good strength, electrical and weathering props. S-glass (Magnesium aluminosilicate) developed at WPAFB for aerospace requirements. Higher E and σ than E-gl- more expensive- higher use temp. S2-glass- low cost S-gl; same composition as S-gl, but differs as to sizing and quality assurance (QA)

  7. Fabric Nomenclature The warp threads are called ends The filling threads are called Picks. Fabric construction is given as density ends x picks per cm Weave (design) is the way the fabrics interlace

  8. Glass/Fiberglass Reinforcement Forms Chopped fiber: Yarn chopped into desired length. Roving: a collection of continuous filaments or strands. Yarn: a collection of filaments or strands suitable for weaving into textile material. Woven Roving: roving woven into fabric. MATS (3 types) - Continuous strand material - Chopped strand material Fabrics: Yarn woven together. - Fabric construction - Size of yarn - no. of yarns - no of yarns in warp (lengthwise) direction - weave pattern (see figures) - plain - satin - basket…etc.

  9. Plain and Stain Weaves Stain Weave: one warp passes over four fills then over one fill. Stain weaves give the highest packing density. Plain Weave: one warp yarn passes over one fill

  10. Properties Chopped fibers (Sheet Molding Compound SMC) Prop E-gl S2-gl Flexture σ(ksi) 22-24 30-34 E(msi) 1.8-2.4 1.9-2.2 Compression. σ(ksi) 27.2-36.0 65.7 Tensile σ(ksi) 10.8-13.1 18.8 E(msi) 1.9-2.4 2.0-2.2 Cont. Fiber gl/fabric/ ep resin Prop E-gl S-gl Flexture σ(ksi) 82.4 113.6 E(msi) 3.5 4.0 Compression. σ(ksi) 62.0 65.7 Tensile σ(ksi) 57.2 81.6 Rasin cont. 37.5 34.4

  11. Advantages and Disadvantages • Advantages: • Manufacturing economy • Inherent symmetry in balanced fabric • Comfortable to complex shapes • Flexibility in fabric design • Disadvantages: • Mechanical properties inferiors to tape • Fabric distortion (bowing & skewing) can cause warping Surface treated fibers: Fiber coated with chemical coupling agents- these form chemical bonds between the fiber's surface and the matrix resin. This is applied as a sizing or finish. Size: applied at the bushing Finish: applied to the roving or fabric

  12. Cont. Finishes: help protect the fibers, provide improved composite mechanical properties such as shear strength, resistance to moisture, chemical degradation, ets. Coupling Agents: have dual functionality; one end reacts with gl, while the other end reacts with the resin. • Coupling agents provides: • Mechanical improvement • - adhesion • - shear • - elongation • Wetting • Environmental resistance • -moisture • - chemical agents • - temperature

  13. Continuous- Fiber Reinforcement • No symmetric • No uniformality • No flat surface • Cheap because no control on them 0/90 Fabric Chopped- Fiber Reinforcement Three dimensional Two-Dimensional

  14. Reinforcement Form Fiber Volume Fraction Modulus Tensile Strength Typical Range Msi Gpa Ksi Mpa Unidirectional Balanced Fabric Discontinuous Random- 2D (MAT) Discontinuous Random- 3D 60 % 50 % 15 % 15 % 50-70 40-70 10-50 10-20 6.5 3.8 1.3 1.1 45 26 9 8 150 60 15 8 1020 413 103 55 Influence of Reinforcement FormE-Glass/Epoxy Composite Properties

  15. Fiberglass Applications Applications: Automotive: body panels, springs. Aerospace: flooring, secondary structures Pressure bottles/tanks- storage tanks, fuel cells Helicopter components- blades, fuslage Consume related- sporting goods, boating Electronics- printed wiring boards

  16. Racing Bike Carbon Fiber Composites

  17. Assignment & Project 3 Papers: 3 research that have innovative addition. Submit the originals and 1-2 pages summary. A project: - make groups of 4-5 students. - Pick up an application as a project. - Prepare to present it in a form of a report and presntation - Include Literature review, advantages, disadvantages, assembly,

  18. specification development • : Functional design: Design a standard SCUBA diving tank with compositematerials. • Design specifications: • Tank must utilize existing valves • Tank must be 80 cu.ft. volume • Tank must be 26.1”x7.2” dimensions • Tank must accommodate at least 3000 Psi • Tank must weigh less than 33 lb • Tank must have service life of at least 15 Years • Tank must be easily assembled and maintained • Working Temp: -32 ° ~200° F

  19. Design Criteria • Tank must have adequate safety features • It is desirable that the tank can be easily scalable • It is desirable that the tank’s sale price is reasonable • It is desirable that the tank’s weight be as less as possible Deliverables • Material selections • Assembly drawings • Inspection and testing • Repair and service life prediction • Final report

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