1. Do not read so much, look about you and think of what you see there – Feyman Do not read so much, look about you and think of what you see there – Feyman

2. Crystal whiskers - SiC

3. Composites - polymer matrix composites (PMCs) Fibers: mainly - glass (GFRPs), carbon (CFRPs), aramid, others - B, SiC, Al 2 O 3 Fibers: mainly - glass (GFRPs), carbon (CFRPs), aramid, others - B, SiC, Al 2 O 3

4. Composites - polymer matrix composites (PMCs) Fibers: mainly - glass (GFRPs), carbon (CFRPs), aramid, others - B, SiC, Al 2 O 3 Fibers: mainly - glass (GFRPs), carbon (CFRPs), aramid, others - B, SiC, Al 2 O 3

5. Composites - polymer matrix composites (PMCs) Fibers: mainly - glass (GFRPs), carbon (CFRPs), aramid, others - B, SiC, Al 2 O 3 Fibers: mainly - glass (GFRPs), carbon (CFRPs), aramid, others - B, SiC, Al 2 O 3

6. Composites - polymer matrix composites (PMCs) Fibers: mainly - glass (GFRPs), carbon (CFRPs), aramid, others - B, SiC, Al 2 O 3 Fibers: mainly - glass (GFRPs), carbon (CFRPs), aramid, others - B, SiC, Al 2 O 3

7. Composites - polymer matrix composites (PMCs) Fibers: mainly - glass (GFRPs), carbon (CFRPs), aramid, others - B, SiC, Al 2 O 3 Fibers: mainly - glass (GFRPs), carbon (CFRPs), aramid, others - B, SiC, Al 2 O 3

8. Composites - polymer matrix composites (PMCs) Carbon fibers frequently used as woven fabrics impregnated with an epoxy

9. Composites - polymer matrix composites (PMCs)

10. Woven carbon fiber fabrics in auto industry - 2006 BMW M6 - roof (unpainted) 'vette Z06 - front fenders, wheel wells, floor Porsche Carrera GT ($440,000) - frame Scion accessories - gear shift knob ($49), fuel-filler door ($39), roof pillar appliqués ($75-189), etc.

11. Composites - polymer matrix composites (PMCs) Matrix

12. Composites - polymer matrix composites (PMCs) Very common - polyesters, vinyl esters

13. Composites Role of matrix in FR composites: a. transfer stresses betwn fibers b. provide barrier to environment c. protect fibers Role of matrix in FR composites: a. transfer stresses betwn fibers b. provide barrier to environment c. protect fibers Matrix/fiber bond: matrix must wet fiber physical & chemical bond desirable mechanical interlocking Matrix/fiber bond: matrix must wet fiber physical & chemical bond desirable mechanical interlocking Fibers frequently coated w/ coupling agent

14. non-coupled Composites coupled

15. Composites Fibers - variables amount fiber length distribution orientation Fibers - variables amount fiber length distribution orientation

16. Composites Fibers - variables amount fiber length distribution orientation Fibers - variables amount fiber length distribution orientation Fiber orientation can be random aligned intermediate Fiber orientation can be random aligned intermediate

17. Composites

19. Assignment: Review today's classnotes a. PMCs - fibers b. vinyl esters c. matrix/fiber bond d. fiber characteristics & behavior Read pp. 538-563 Assignment: Review today's classnotes a. PMCs - fibers b. vinyl esters c. matrix/fiber bond d. fiber characteristics & behavior Read pp. 538-563

20. Composites - polymer matrix composites (PMCs) Role of matrix in FR composites: a. transfer stresses betwn fibers b. provide barrier to environment c. protect fibers Role of matrix in FR composites: a. transfer stresses betwn fibers b. provide barrier to environment c. protect fibers Slow crack growth deflect crack tips redistribute stresses around crack tips bridge crack tips Slow crack growth deflect crack tips redistribute stresses around crack tips bridge crack tips