Validation of two-dimensional calculations of free edge delamination in laminated composites

In this paper the use of two-dimensional calculations, which are often applied for the analysis of free edge delamination in a T-bone specimen, is validated by comparing the results with complete three-dimensional calculations. The specimen that is discussed shows mode-I delamination in the midplane of the specimen which is modelled in the analysis by means of an orthotropic damage model for interface elements. Although symmetry does not exist because of the material lay-up, use is made of assumed symmetry conditions, which are validated by analyses without symmetry conditions. II is shown that a two-dimensional analysis suffices for the determination of the ultimate load bearing capacity of the strip, but that a three-dimensional analysis is necessary to obtain a reliable view of the evolution of the delamination zone. (C) 1999 Elsevier Science Ltd. All rights reserved.