DAMAGE CRITERIA FOR THE STUDY OF IMPACTED COMPOSITE LAMINATES

Modelling the behaviour of laminated composite structures under tow-ve locity impact loading (i.e. m<3 kg, v < 6 m s(-1)) is closely linked t o the study, of the damage in the impacted structure. In this framewor k, the state of str ess is multiaxial. Local observations al e not eas y to carry out, nevertheless the drop-weight set-lip based on split Ho pkinson pressure bar metrology gives the force/time and displacement/t ime relationships on the scale of the impactor composite-plate system (global scale). Having in mind that this kind of macroscopic measureme nt is not a direct representation of damage chronology on the local sc ale (material and layer scale), we have developed a: hybrid approach a llowing an efficient use of experimental results and, conversely, of n umerical ones by identifying local damage criteria (global experimenta l measurements, local numerical identification). The last part discuss es the methodology applied to symmetrical 10-ply glass-epoxy 0/90 lami nates. (C) 1998 Elsevier Science Ltd. All rights reserved.