Effect of Strength Eccentricity on Torsional Behaviour of RC Frame Buildings
Tóm tắt
This study attempts to understand the inelastic seismic behaviour of asymmetric multistory RC buildings using non-linear dynamic time history analysis. Both inherently asymmetric and artificially generated eccentric building models were considered. Two categories of artificially generated models were considered. In the first category, groups of mass symmetric systems (MSS) having strength, stiffness and both strength and stiffness eccentricities were considered. In the second category of models, mass eccentricity was introduced in otherwise symmetric models. Building systems were modelled as 3D space frame with lumped plasticity. The response is evaluated using the peak rotational ductility demand of beams of the different frames as measures of their inelastic response. Investigations of first category of artificially generated MSS showed that the response can be better co-related with the strength eccentricity. The results from the second category of systems not designed for torsion indicated that there is significant variation in the beam ductility demands of different frames, whereas systems designed for torsion indicated a shift in the center of strength towards the center of mass and exhibited almost uniform ductility demand in beams of various frames for smaller eccentricities.
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