Failure of Sandwich Composite Structure Containing Face-sheet/Core Disbonds - an Experimental Study

During this study, a number of honeycomb sandwich specimens containing circular manufactured disbonds were loaded to failure in bending. Particular emphasis was placed on accurately identifying the occurrence of disbond buckling and growth initiation, as these two events are inherently difficult to monitor. This study aims to fill a large gap in the published literature regarding experimental results for disbonded sandwich structures. The test results are presented in three sections; firstly, the buckling, growth initiation and failure loads are presented for each of the six tested configurations; secondly, the method of identifying disbond buckling is explained; and thirdly, the method of identifying disbond growth initiation is presented. Finally, conclusions are drawn and there is discussion of the results in terms of damage tolerance and design considerations.