Strojnicky Casopis 50, 241-252, 1999


L.J. Martikainen¹ and F.G. Rammerstorfer²

¹Laboratory of Technical and Applied Mechanics, HUT, Espoo, Finland
²Institute of Lightweight Structures and Aerospace Engineering, TU Wien, Vienna, Austria

Abstract - Thin-faced sandwich panels with a soft core are sensitive to failure under localized loads. Support reactions of continuous panels can easily cause local failures, such as buckling of the faces or crushing of the core, at intermediate supports. These failures result in inelastic deformations in the core and, further, in the reduced stiffness and load-carrying capacity of the sandwich panel. This paper studies the Finite Element modelling of local failures. The core of the panel is modelled by continuum elements and the faces by beam elements. The continuum model for the core enables the use of an elastic-plastic material model, called the crushable foam model, to take the hydrostatic pressure dependent yield of the core material into account. Three-point bending tests on panels with steel faces and a core made of polystyrene foam or structural rock wool could be satisfactorily simulated by FE-calculations.