Southward, T: Buckling and Growth of Disbonds in Honeycomb S

The response of honeycomb sandwich structure to disbond damage, in a compressive stress field, has been assessed. Two types of disbond were considered; those extending through the full width of a panel (through-width) and those enclosed within the panel boundaries (embedded). For each type of disbond the failure process was established through four-point bend testing of 56 sandwich specimens. For both types of disbond, failure was found to be governed by buckling-driven disbond growth and, consequently, models of buckling and disbond growth were developed. Linear Winkler beam and plate models were used to predict disbond buckling. Non-linear Winkler beam and plate models were then developed to predict post-buckling behaviour and the initiation of disbond growth, through a fracture mechanics analysis. All models showed excellent correlation to test data. The models developed may be used to assess the criticality of disbond damage in sandwich structure having thin-gauge, composite face-sheets.