A dynamic stiffness formulation for the analysis of secondary systems

✍ Scribed by Bernal, Dionisio

• Publisher: John Wiley and Sons
• Year: 1999
• Tongue: English
• Weight: 207 KB
• Volume: 28
• Category: Article
• ISSN: 0098-8847
• DOI: 10.1002/(sici)1096-9845(199911)28:11<1295::aid-eqe867>3.0.co;2-2

✦ Synopsis

Formulation of a frequency-domain substructure approach for the analysis of secondary systems is presented. The total system contemplated includes the primary structure, the secondary system, and the foundation medium, which is also treated as a substructure. A dynamic sti!ness matrix in physical co-ordinates characterizes each one of the substructures. Elimination of the internal degrees of freedom of the primary structure prior to assembly of the equations for the coupled system is carried out with the aid of a truncated set of unconstrained normal modes. Accounting for the residual static #exibility of the truncated modes obviates potential problems of rank de"ciency resulting from modal truncation. The formulation contemplates an arbitrary multi-component scattered motion at the soil}structure interface and imposes no limitations on the con"guration of the primary or the secondary system. Connectivity between the systems is treated as an arbitrary linear relation between selected co-ordinates in each substructure. This feature is shown to be useful for modelling the commonly encountered situation where secondary systems are attached to torsionally eccentric structures.