Experimental seismic investigation of appendages in structures

Abstract

In this study, the behavior of light appendages mounted in structures
\nthat respond inelastically to earthquakes was examined experimentally and analytically.
\nA simple interpretation of an elastic detuned appendage is derived. It is shown that
\nthe tuned appendage can be considered as a limiting case of the detuned appendage and that
\nthe transition can be approximated using the slightly detuned appendage. In the case of a
\nSDOF inelastic supporting structure, the actual structure is replaced by an equivalent
\nlinear system. In the case of a MDOF inelastic supporting structure, the concept of modal
\nductility is used to obtain equivalent linear modes.
\nA series of experiments of SDOF appendages mounted on one- and two-story structures
\nwas performed. The combined systems were subjected to earthquake motions. Good agreement
\n~as obtained between the measurements and the maximum appendages responses evaluated using
\nthe suggested procedure.
\nThe main conclusion of this study is that the concepts of equivalent linear system and
\nmodal ductility provide a good tool for estimating the maximum response of an appendage
\nmounted on an inelastic supporting structure. The expected accuracy is about the same for
\nelastic and inelastic supporting structures.