STRUCTURAL CHARACTERIZATION AND MODELLING OF METALLIC GRID STIFFENED PANELS FOR AEROSPACE INDUSTRY

The aim of this study is to develop a technique for accurately capturing the actual behaviour of metallic grid stiffened panels in static, buckling and dynamic domains. The focus of the industry on these parts, especially in the aerospace sector, derives from a necessity of obtaining lightweight structures which must be stiff enough for sustaining the loads but at the same time to be drastically lighter. The structure morphology however, does not allow the use of full 3D Finite Element models for structural validation due to the high computational effort and the consequent industrial inapplicability. Alternative solutions for the structural characterization of these structures must be explored. Alternative FE models with hybrid approach 2D-1D and full 2D approach are studied by taking in consideration additionally the machining fillet radius, a parameter usually neglected in the design phase. Finally, all the alternative FE solutions are validated with a series of specimens subjected to static, dynamic and buckling tests, showing the degree of discrepancy introduced by the downscaling of the models.