Modal Analysis of a Reinforced Concrete Frame in Various States of Damage
The purpose of this paper is to report selected results of an experiment in which two, natural size r/c frames were put on shaking table and subjected to a sequence of seismic excitations with increasing intensity interlaced with low level, diagnostic tests. The shaking table experiment aimed at working out new methodology for monitoring vibrations of r/c structures to assess their state. Characteristic decrease of natural frequencies and increase of structural damping was observed and analyzed in detail. It was interesting to note 20 per cent drop in natural frequencies prior to visual detection of any cracks.
W.M. Ostachowicz, J.M. Dulieu-Barton, K.M. Holford, M. Krawczuk and A. Zak
Z. Zembaty and M. Kowalski, "Modal Analysis of a Reinforced Concrete Frame in Various States of Damage ", Key Engineering Materials, Vols. 293-294, pp. 735-742, 2005