Delamination Toughness Characterization of Laminated Composites

Abstract

The state‐of‐the‐art in delamination toughness characterization is reviewed. Widely used methods for determining mode I, II, and mixed‐mode I‐II delamination toughness of laminated composites are first presented. This is followed by a description of the evolving methods for characterizing the mode III and the mixed‐mode toughness under conditions where mode III is present. The effects of mode ratio, temperature, moisture, and interfacial ply orientation on toughness are discussed, as is the representation of static delamination toughness data via failure loci and failure surfaces. Methods are presented to evaluate threshold toughnesses for the onset of fatigue delamination growth and to determine growth rates for stable delamination advance under fatigue loading. The relative advantages of characterizing fatigue delamination growth using energy release rate versus stress intensity factor are also addressed.