Simplified modelling of stiffened panels for simultaneous static and dynamic optimization

Abstract

In this paper a novel simplified structural modelling approach for stiffened panels is presented. It specifically addresses structural response of aircraft fuselage components made from carbon fibre reinforced plastics (CFRP). The proposed method considers structural modelling requirements necessary for structural optimisation with respect to system response under simultaneous static and dynamic loads. The standard explicit finite element (FE) solver LS-Dyna is utilised, providing the framework to regard statics and dynamics as well as non-linearities by material, large deformation and contact. The simplified model is fundamentally composed of shell, beam, and discrete elements. Simulating the structural collapse behaviour of thin-walled CFRP sections under bending load the detailed model provides input parameters for the discrete elements. Furthermore, skinframe- interaction attributes immanent to the present fuselage configuration are reviewed and considered by idealised deformation characteristics. Finally, the present approach is verified through analyses of the detailed model. The results illustrate the benefits of model simplification. Replacing detailed shell model features by beam and non-linear spring elements significantly reduces computational effort. At the same time the accuracy deduction is acceptable considering topological optimisation requirements.