On the Bearing Strength of Fibre Metal Laminates

Abstract

Published work on mechanically fastened joints in composites has demon strated that the influence of lateral restraint on bearing strength is of paramount impor tance. Delamination in conjunction with buckling is frequently observed if there is a lack of lateral restraint (pin-type loading). An investigation is performed on the bearing strength behaviour of fibre metal laminates (ARALL and GLARE) for which similar fail ure modes are found. The theoretical analysis is based on an existing delamination buck ling model for composites. However, an alternative out-of-plane deformation function in corporating a variation with respect to the angle is used. The energy method is extended to include the strain energy of both the aluminium and the prepreg layers. The analytical procedure is supported by finite element calculations, and the theoretical predictions are compared with available experimental data. Very good correlation is obtained. If there is sufficient lateral restraint (bolt-type loading) the bearing ultimate strength can, on the other hand, be predicted by a simple rule of mixtures based on the aluminium volume fraction.