The Distribution of Stress in a Sandwich Conical Shell Panel Under Combined Load

The paper presents an analysis of the stress distribution in the open, cone-shaped, sandwich shell panel. The shell under consideration consists of two load-carrying facings and a core layer of the soft type. The facings are made of an isotropic, compressible, work-hardening material and they are geometrically and physically symmetrical, so they are of equal thicknesses and the same material properties. The core layer resists transverse shear only. The shell under consideration is under combined external load in the form of lateral pressure and a longitudinal force. Different ratios of the longitudinal force to the lateral pressure are taken into account. In each case, the components of the effective stress as well as the effective stress values corresponding to the shell deformation were determined. To determine the stress state which occurs during the shell deformation, the stability equations have to be derived. The effective stress corresponding to the deformations in the shell under consideration can occur within the elastic, elastic-plastic or plastic range. In order to determine the stress distribution in the shell under consideration which corresponds to the on- and post-critical state, the constitutive relations of the Nadai-Hencky deformation theory, alongside the Huber-Mises-Hencky yield condition, are accepted. Analyses show that, in certain cases, there are very large differences between the values of the components of the stress state. In such cases, it seems to be possible to omit the components with small values.