ABSTRACT
Substructuring and Superelements Substructuring is the division of a structure into smaller
regions or substructures. This division may be extended in a recurrent way to the interior of some substructures, defining a multi-level substructuring. The substructures composing directly the structure belong to the highest (or first) substructuring level. The nodal points and respective degreesof-freedom incident in a substructure are of two kinds: • internal: situated in the interior, thus belonging only to
the substructure. • external: placed on the substructure boundary; they may be-
long simultaneously both to this and to other substructures, or to the global structure boundary. Initially, each substructure is analysed independently,
ocurring the condensation of its stiffness matrix and its loads vector with relation to its external nodes. Afterwards, it takes place the assembling of these matrices and vectors, determining the global structure stiffness matrix and loads vector. It follows the displacements evaluation of the nodes placed on the interfaces between the first level substructures. Finally, the separate analysis of each substructure is retaken, determining the displacements of its internal nodes and the efforts on its constituent elements.
