An interface element for the modelling of localized deformations in curved shells

Folding of thin shells around localized lines occurs in several situations of engineering interest, such as in buckling induced deformation, as consequence of crash, in industrial processes like metal forming, in deployment of folded membranes, in packaging related processes. In this paper an interface element, allowing for displacement and rotation discontinuities, to be placed between two adjacent 4-node Mindlin-Reissner shell finite elements, is developed for a computationally effective simulation of this kind of localized phenomena. The large displacement and rotation kinematics of the interface element is discussed. To test the element formulation, a simple coupled membrane-bending elastic-plastic behavior is assumed. The element is used for the simulation of few examples taken from the literature, where the structural response is characterized by the formation of plastic hinges, exhibiting good accuracy and computational effectiveness.