1. There is a demand in the market for producing lighter and stronger composite materials.There is a demand in the market for producing lighter and stronger composite materials. Composites most widely used in aerospace.Composites most widely used in aerospace. compose of high-strength fibers that embedded in an matrix.compose of high-strength fibers that embedded in an matrix. Composite materials are very stable because they are high strength and weight ratio.Composite materials are very stable because they are high strength and weight ratio. Somnang Rom,12/1/04 ELM 4701

2. What is a composite? Composite: are combinations of two materialsComposite: are combinations of two materials -reinforcing phase: compose of fibers, and much stronger with low densities. -reinforcing phase: compose of fibers, and much stronger with low densities. -matrix phase: ductile or tough material -matrix phase: ductile or tough material The shape and geometry of the finished part formed by a mold or other tooling during processing.The shape and geometry of the finished part formed by a mold or other tooling during processing. fibers matrix

3. Structural and application: composite have lower densitycomposite have lower density greater strength and stiffness than aluminumsgreater strength and stiffness than aluminums lighter structure and it can carry the same load as Al alloy. lighter structure and it can carry the same load as Al alloy. Studies conducted by Boeing indicated that 38% composite structural weight can result in a 40% reduction in empty weight, 39% reduction in wing area and a 33% fuel saving, compared to an aircraft of conventional metal structures.Studies conducted by Boeing indicated that 38% composite structural weight can result in a 40% reduction in empty weight, 39% reduction in wing area and a 33% fuel saving, compared to an aircraft of conventional metal structures. other advantages: Fatigues testing in of composite structure demonstrated their high resistance to cracking. Fatigues testing in of composite structure demonstrated their high resistance to cracking. Composite materials are very stable and are not subject to corrosion as metal structures.Composite materials are very stable and are not subject to corrosion as metal structures.

4. Three common fiber configuration for composite reinforcement

5. matrix fiber Uniaxial stressing of a composite With continuous fiber reinforcement Define terms: E f elastic modulus of fiber,,, E m elastic modulus of matrix V f volume of fiber V m volume of matrix Prosperities of composite: Formula for elastic modulus Of the composite:

6. (E-glass) fiber modulus =72.4X10^3 Mpa The strain Vs. stress Composite(70%fibers) Modulus=52.8X10^3Mpa (Epoxy) matrix modulus =6.9X10^3Mpa

7. Material Stiffness (psi)Yield Strength (psi) Density Lb/in 3 Cost $/lb Steel (1040) $.50/lb 30x10 6 60,000.3 Aluminum 6061 T-6 $4.00/Lb 10x10 6 35,000.10 Graphite& Epoxy $8/Lb 8x10 6 60,000.065 Fiberglass & Polyester $1.8/Lb 1.2x10 6 30,000.055

8. Conclusions: -- Composite material system is light weight and providing a high impact strength. ---Fibers provide high strength and modulus in a polymeric matrix and also provides ductility. --It is also proven fact that fibers are much stronger than the matrix.

9. Reference www.engr.sjsu.eud/WofMatE/Composites.htm www.global-defence.com/2003/uavs_03.htm Materials Science For Engineerings fifth edidion, by James F. Shackelford Copy write: 2000 by Prentice-Hall