Multilevel optimization of aerospace and lightweight structures

The design and optimization of aerospace structures is a very complicated task. The complexity of the structural configuration, combined with a wide range of possible loading and boundary conditions leads to the need for a multilevel optimization approach. Over many years the specialist panel design code VICONOPT has provided a fast and efficient tool for the analysis and design of typical aerospace structures such as longitudinally stiffened wing panels. Procedures are based on an ‘exact’ strip algorithm which allows critical buckling loads and natural frequencies to be determined with absolute certainty. A significant advantage of this approach over finite element based procedures is the dramatically reduced computation time required. When integrated into a multilevel optimization environment the software thus becomes particularly valuable. Following a general introduction to VICONOPT, this paper describes the newly developed computer program Viconopt MLO, which acts as a windows interface between the widely used finite element program MSC/NASTRAN and VICONOPT. The software allows the specification of multilevel optimization models, but can also be used as a pre-/post-processor for conventional single level VICONOPT models