Juwhan Kim (juwhan@engin.umich.edu)

and

Kevin R. Collins (kevinrc@umich.edu)

Department of Civil and Environmental Engineering

The University of Michigan

2340 G.G. Brown

Ann Arbor, MI 48109

Abstract

Conventionally, in dynamic analyses of building structures, mass is assumed to be lumped at nodes, and damping is specified in terms of modal damping for convenience.  Although the fidelity of the analyses can be enhanced by increasing the number of nodes of the models, such a refinement scheme is often impractical.

In this study, continuous waveguide beam-columns are employed to create building models in lieu of conventional massless beam-column elements and nodal masses.  This results in an analysis model incorporating distributed mass and damping.  The purpose of the study is to see if such a modeling approach reveals any additional insight into structural behavior that is normally not captured using conventional analyses.  A computer program, implementing spectral analysis, was written and used to analyze 3 building structures in L.A. area. The effect of the distributed mass and damping and the differences from the conventional modeling are discussed.