Damage Tolerance Assessment of Naval Sandwich Structures with Face-Core Debonds

The presence of face-core debonds can seriously reduce the load-carrying capacity and remaining lifetime of sandwich structures. During the past 30 years considerable progress has been made in the modelling and experimental testing of sandwich structures for marine applications, especially with regard to the effects of such debonds. Much of this research has been supported by the US Office of Naval Research. This chapter summarises these developments, with special emphasis on the progress made during the past 10–15 years concerning foam-cored sandwich for naval applications. Fracture mechanics based analysis methods, experimental techniques for characterising face-core interfaces under mode I, mode II and mode III deformations and their combinations, and analysis and testing of structural elements such as beams, columns and panels in the presence of debonds are described. The assessment of observed debond damage in naval sandwich structures is addressed, and the implications for ensuring acceptable damage tolerance are discussed.