Through-thickness reinforcement repair of delaminated carbon–epoxy panels

This paper outlines a through-thickness reinforcement repair (TTRR) technique for delaminated polymer matrix composite (PMC) laminates. This involves drilling holes through the delaminated region and bonding pins into these holes. An experimental study was conducted to assess the effectiveness of the technique to restore the compression strength of laminates with a hole that were deliberately delaminated by controlled lateral loading. The TTRR technique was found to be highly effective, with eight pins bonded in a ring at the mid-span of the circular delamination restoring the compression strength to 93% that of the undamaged laminate. A further increase in pin density was found to provide no additional improvement in the repair efficacy.