Composite Materials

· The photograph shows a buckling failure in a carbon-fiber epoxy-matrix composite (cfrp) . Loading was parallel to the fibers (horizontal in the picture).
· The large V_f case is that of practical importance. The buckling stress is estimated as: σ_bC = G_m / (1 - V_f )
where G_m is the matrix shear modulus.
· This expression overestimates the buckling stress by about a factor of two compared to the experimental value

From: Hull, "Introduction to Composite Materials,"
Cambridge (1992)