Question

Which of the following statements are correct with reference to glass fiber reinforced composite?

1. They are isotropic

2. Coefficient of expansion of fiber should match closely to that of the plastic material.

3. The fiber and plastic material should be chemically compatible with each other
1. 1, 2 and 3
2. 1 and 2 only
3. 2 and 3 only
4. 1 and 3 only
5.

Answer 1

Correct Answer - Option 3 : 2 and 3 only

Explanation:

• The glass fiber reinforced composites are composed of fibers embedded in the glass matrix material.
• The glass fiber reinforced composite are having direction-dependent properties so these are not isotropic in nature so statement 1 is incorrect.
• Fibers are small in diameter and when pushed axially, they bend easily although they have very good tensile properties. These fibers must be supported to keep individual fibers from bending and buckling.
• So, in order to ensure compatibility with the glass matrix, the coefficient of expansion of fiber should match closely to that of the plastic material so statements 2 and 3 are correct.

Note: If statement 1 is incorrect then referring to the options, the only possible correct option will be option 3.