Demonstration of torsional behaviour using vibration-based single-storey model with double eccentricities

Abstract

The use of single-storey schemes appears necessary in order to investigate lateral-torsional coupling in building structures. In this paper, the torsional behaviour of an eccentric single-storey system based on undamped free vibration analysis has been investigated with particular emphasis on double eccentricities. An eccentricity between the center of rigidity and the center of mass in a building system causes the different torsional behaviour during a seismic loading. This approach reveals clearly how the double eccentric system behaves in relationship with the natural frequencies and modes and translational or torsional motion of the modeling system. From the parametric analysis of such an approach the determinative role of the distance from the center of mass to the center of rotation corresponding to the torsional and lateral stiffness ratio of the system becomes an obvious means of defining the torsional behaviour. From the outcome of applying the model, the building model can be classified as Torsionally Stiff (TS) and Torsionally Flexible (TF) based on the way the model has been configured in terms of the loci of the centers of rotation.

Recent Advances in Vibrations Analysis

“…The estimation of torsional-translational response of simplified procedure subjected to a strong ground motion, is a key issue for the rational seismic design of new buildings and the seismic evaluation of exacting buildings. This section is a vibration-based analysis of the simple one-storey model with double eccentricities, and it would be a promising candidate as long as buildings oscillate predominantly in the two lateral directions (Tabatabaei and Saffari, 2010).…”

Torsional Vibration of Eccentric Building Systems

“…This section is a vibration-based analysis of the simple one-storey model with double eccentricities, and it would be a promising candidate as long as buildings oscillate predominantly in the two lateral directions (Tabatabaei and Saffari, 2010).…”

“…8. CR * and CM * denote the new locations of the centers of rigidity and mass at any time instant, respectively (Tabatabaei and Saffari, 2010).…”