thermal coefficients are negligibly small and it changes sign as the fiber volume fraction


is varied. At about 40% fiber volume fraction the longitudinal thermal coefficient is


almost equal to zero. The transverse thermal coefficient also reduces due to increase in


fiber volume fraction because of the reduction in the effect of matrix material. The results


show the micromechanics method is useful to develop composite materials for various


applications by changing the combination of the constituent materials.


0 01 02 03 04 05 06 07 08 09
 Fiber volume fraction


Figure 2-6. Longitudinal coefficient of thermal expansion with various fiber volume
 fractions for glass/epoxy and graphite/epoxy laminates.




 Square Cell (Glass/Epoxy)
 -A- Hexagonal(Glass/Epoxy)
 20- Square Cell (Graphite/Epoxy)
 -- HexagonalCell (Graphite/Epoxy)

 o
 v 15
 15 10, Carbon/Epoxy
 0
 S10 -

 E Glass/Epoxy
 5 -


 0 01 02 03 04 05 06 07 08 09
 Fiber volume fraction



Figure 2-7. Transverse coefficient of thermal expansion with various fiber volume
 fractions for glass/epoxy and graphite/epoxy laminates.


-A-- Square Cell (Graphite/Epoxy)
-0- Hexagonal Cell (Graphite/Epoxy)
A- Square Cell (Glass/Epoxy)
 -0- Hexagonal Cell (Glass/Epoxy)

 Glass/Epoxy




 Carbon/Epoxy