Conceptual studies of a composite–aluminum hybrid wing box demonstrator

This paper presents a study of two hybrid composite–aluminum concepts of a winglike structure which is exposed to mechanical and thermal load. The aim of the study is to determine the most suitable hybrid concept to be used in structural fatigue and static testing. In both concepts, the mass is optimized with respect to two different sets of requirements, one of which is currently in use in the fighter aircraft industry and one which is a modified version of the current requirement set. The issues considered in the study are mass, thermal behavior, buckling, bolted joints, failure criteria and fatigue damage, and they are examined in the frame of both requirement sets. The results indicate the order of criticality between the different criteria in the different parts of each concept. Also, the comparison of two requirement sets shows the influence of the modified criteria on the hybrid concepts and their mass. Based on the mass and the structural behavior in a thermal–mechanical loading, one of the hybrid concepts is chosen for further studies and testing.