The environmental stress corrosion cracking of glass fibre-reinforced laminates and single E-glass filaments

The environmental stress corrosion cracking of epoxy/glass fibre crossply, unidirectional coupons and single E-glass filaments have been compared. At initial applied strains > 0.15% the resin does not protect the fibres as shown by their equivalent failure times. The failure occurs in the environment and planar fractures occur because of the localized stress in the load bearing plies adjacent to a transverse crack in the 90° ply of the 0°/ 90°/0° coupons. These transverse cracks result from stress corrosion of the glass/resin interface, which leads to a reduction of the transverse cracking strain. At applied strains < 0.15% fracture occurs within the unexposed half of the coupons and is thought to be caused by rapid transport of glass corrosion products where they crystallize within the coupon. This phenomenon is also responsible for the progressive transverse cracking that occurs in both the 0° and 90° plies of the unimmersed half of the crossply coupon under zero load.