Free vibrations of multi-storey, multi-bay reinforced concrete frames with strong column – weak beam model.
Keywords:
Capacity design concept; Strong column – weak beam model; multistorey – multibay frames; Finite degree of freedom; Classical displacement method; Fundamental frequency.Abstract
This paper investigated the dynamic responses of multistorey, multibay reinforced concrete framed buildings, using the concept
of strong column – weak beam model. In the course of this work, three simulated frames were dynamically investigated; the
natural frequencies of each frame at various ratios of column flexural strengths to beam flexural strengths were numerically
evaluated at a given concrete grade and unit weight; using classical method of displacement; and subsequently, the fundamental
tone of vibration at a given c b EI EI ratio was explicitly compared with the fundamental tone of vibration of the same system,
evaluated using the Shear Building model approach. And from the results obtained, it was found that the column flexural strength
demand for dynamic stability varied in accordance with the number of floor levels of the frames. This paper, therefore,
establishes no fixed empirical value for the ratio of column flexural strength to beam flexural strength; and consequently
recommends that the column flexural strength participation factor(s) in the analysis of dynamic stability of frames with strong
column – weak beam concept be adequately evaluated, using Classical method of analysis.
