Impact resistance and tolerance of interleaved tape laminates

This paper presents and discusses the results of low-velocity impact and co mpression-after-impact (CAI) tests conducted on interleaved and non-interle aved carbon/epoxy tape laminates. Olefin film interleaves provided a strong interface bond, resulting in a reduction in projected damage area. These i nterleaves changed the stress distribution under impact and restricted dela mination formation at the ply interface. An investigation into the compress ion behaviour of these laminates revealed a reduction in undamaged strength using olefin interleaves. This was attributed to the lack of lateral suppo rt for fibres at the fibre/interleaf interface, allowing fibre microbucklin g to occur at a low load. Low modulus copolyamide web interleaves resulted in an increase in damage area and minor changes to CAI strength. Examinatio n of laminate cross-sections revealed that this was due to both the open st ructure of the interleaf and Door resin/interleaf adhesion. High shear modu lus polyethylene interleaves resulted in a significant decrease in damage a rea at various impact energies, with CAI strength improved compared to the non-interleaved laminates. (C) 2000 Published by Elsevier Science Ltd. All rights reserved.