ABSTRACT of the Doctoral Thesis

Development of Efficient Finite Shell Elements for the Analysis of Sandwich Structures under Large Deformations and Global as well as Local Instabilities

by Alois Starlinger (1990)

Based on a sandwich shell theory assuming antiplane conditions for the core, finite element algorithms for large displacements are developed by applying the 3D degeneration principle. In one formulation the sandwich structure is transformed into a quasi-homogeneous shell by smearing out the material parameters over the shell thickness, in an alternative formulation the sandwich shell is described by a layer model, the stiffness terms being integrated independently for the face layers and the core. The influence of local effects such as thickness reduction induced by bending moments (similar to the Brazier effect) and local instability phenomena (e.g. wrinkling of the face layers, shear failure of the core, intercell buckling) on the global deformation and stability behavior can be taken into account by the developed shell element. Some typical examples show the applicability of the algorithms.

revised 951214 (hjb)