Interlaminar fracture behaviour of laminated composites

The interlaminar fracture behavior of composite laminate under full range o f in-plane loading conditions has been investigated. Loading conditions fro m pure mode I through Various mixed mode I/II ratios up to pure mode II hav e been generated by the aid of the proposed compound version of the compact tension shear specimen. From the experimentally measured critical loads th e mode I, mode II and the various mixed mode I/II critical energy release r ates at crack initiation have been determined by the aid of the finite elem ent method and the modified virtual crack closure integral method. Based on these results the parameters for a fracture criterion for the composite un der consideration have been determined. (C) 2000 Elsevier Science Ltd. All rights reserved.