Originally Posted by
unterhausen
the fibers are really only stiff in tension, but in tension their stiffness dwarfs that of the matrix. The matrix adds very little stiffness, but obviously it is required for structural stability.
I can't really agree with that. The matrix glue has to complement the fiber choice.
The highest modulus Carbon with a soft curing epoxy isn't going to be a stiff frame.
Different types of epoxy have wildly different strength ratios. West epoxy is very highly thought of as a binding resin but something like Poly Epoxy has double the strength.
If the carbon is really only providing tensile strength then it has to be bracing itself against something with good compression resistance to show that strength.
West epoxy has about 15,000 psi of compressive strength while Poly Epoxy is 32,000.