Compression properties of z-pinned sandwich composites

Compression properties of z-pinned sandwich composites are investigated. A sandwich composite consisting of fiberglass skins and a polyvinyl chloride foam core was reinforced with fibrous composite pins. The standard z-pinning technique is used to reinforce composite laminates and sandwich materials. The composites were tested using 40mmx40mm specimens in flat-wise compression according to ASTM C393 at a loading rate of 1 mm/min. The modulus and strength were found to be increasing at a linear rate with the pin content, with these properties more than doubling with every 1% of z-pins. The results show that compression property values of the pins are highly sensitive to their orientation in the foam core. Large improvements to the compression modulus and strength of sandwich composites are predicted using small amounts of z-pins made of fibrous composite, metals or carbon nanotubes .