Cut-outs; door surrounding

Abstract

Cut-outs are highly fatigue sensitive due to the large stress concentrations. In aircraft fuselages these cut-outs are quite large in the case of the windows and doors. Much effort is usually needed to limit the stresses and displacements around these cut-outs. Displacements are mainly controlled by edge members and stresses are controlled by doubler packages. The stress level may be increased through the application of Glare in the doubler packages, due to the improved fatigue behaviour compared to conventional aluminium. Glare also presents the possibility of tailoring the material to the load, i.e. fibres aligned with the load. For the door corners this may result in the use of Glare with a 45 degrees orientation. FE analysis defined the total doubler package and a test programme was run to confirm the behaviour of the material and to predict the crack behaviour of the Glare door corner.