Delamination initiation around cut holes in symmetric laminates: Effects of PET film interleaving
The effects of PET film interleaving on delamination initiation in centrally notched (????/0)s composite laminates with fiber directions ?? = 15??, 30??, 45?? and 60?? respectively have been investigated. A pair of interleaves were selectively placed at delamination prone interfaces in each laminate. The circular holes were cut in glass-epoxy laminates using high-speed drilling (HSD) and abrasive waterjet cutting (AWC) in order to compare the influence of hole surface finish with interleaving. Surface profilometry was used as a nondestructive technique for detecting delamination onset during tensile testing. It was found that although HSD interleaved holes were the roughest, the delamination onset stresses were significantly increased particularly for 30?? < ?? < 60??. For ?? = 60??, however, delamination onset was unaffected by either hole surface finish or interleaving.