Fragmentation tests have been conducted on elementary aluminium matrix/silicon carbide fibre composites. The results obtained are not consistent with Kelly and Tyson's load transfer theory widely used to determine the load transfer capacity in plastic matrix composites. From these results and the conducted observations, a model has been developed, trying to take into account the hardening of the matrix. The results obtained with this model are used to point out further necessary developments of the theory. (C) 1997 Elsevier Science Limited.