On some features of a plate hybrid-Trefftz displacement element containing a hole

The paper deals with the modelling of riveted assemblies for full-scale complete aircraft crashworthiness. To perform computations aiming at locating rupture initiation in a structure featuring more than 100,000 rivets, it is necessary to model the assembly areas using "super-elements''. If rivet elements have been developed, perforated plate super-elements are still lacking. Thus, the paper focuses on plate super-finite element formulations featuring defects, in particular holes. An original 8-node plate element containing a hole has been selected to discuss on the possibility to extend its formulation from linear (elasticity) to non-linear problems (impact). However, since little is known about the features of super-elements containing a hole, it is first attempted to clarify the properties of the selected existing super-element. This kind of element is defined according to the introduced nomenclature, and the features of its interpolation functions are highlighted. The location of stress fields computed by this super-element is proved to be in close agreement with results provided by standard FE calculations. This super-element exhibits also computational efficiency. These features encourage one to pursue the extension of this super-element formulation to large high plastic strains and strain rates, aiming at localising rupture initiation when performing crashworthiness computations of structures with many rivets and holes. (C) 2010 Elsevier B.V. All rights reserved.