Discrete tailored asymmetric sandwich structures

摘要

Composite sandwich constructions are now widely used in primary aircraft airframe structures and outstand by their high bending and stability performance. These structures are typically characterized by a continuous core which extends over the entire structural bay perimeter confined by adjacent framework structural members. This paper presents a novel design approach of asymmetric sandwich structures which is based upon a tailored discretization of the core area over the bay perimeter and enables an important increase of the weight efficiency of traditional sandwich shells. The discretization pattern of the core is a result of a topographic optimization of the bending stiffness with respect to an in-plane loading. The paper describes the basic rationale of the design approach and demonstrates its technological feasibility. The mechanical behavior is predicted by standard linear and non-linear numerical tools and verified by shear tests. Furthermore, the design approach is exemplarily applied within the context of real helicopter airframe structures hence proving its functional and practical suitability.