Structures are complex objects and a simplified model is necessary to conduct numerical analyses. Nonetheless, the accuracy of the numerical model is fundamental to predict the seismic response of the structure effectively. Different numerical models can be used to simulate real structures and currently one of the most popular numerical models for RC members is the fibre model. Despite the widely recognized accuracy of fibre models, it has been observed that the adoption of fibre modelling for beams in RC framed structures with rigid diaphragm determines fictitious axial forces in beams that distort their nonlinear behaviour. This undermines the accuracy of the seismic response of the structure evaluated by nonlinear analysis and may lead to inaccurate predictions of displacement demand, force demand of the structural members and yielding pattern. To overcome this shortcoming, the authors propose the insertion at one end of each beam of a zero-length element, named axial buffer element, which has a large axial deformability and is extremely rigid for shear and bending moment. This paper investigates the influence of those fictitious axial forces in RC beams on the response of the structure. To this end, pushover analyses are run to determine the seismic response of an RC frame designed to sustain seismic forces and an RC frame designed to sustain gravity loads only. For each frame, the seismic behaviour of the structure without axial buffer element is compared to that of the structure with buffer element.
|Titolo:||The combined effect of rigid diaphragm and beam modelling in RC buildings under pushover analysis|
MARINO, EDOARDO MICHELE (Corresponding)
|Data di pubblicazione:||2018|
|Appare nelle tipologie:||4.1 Contributo in Atti di convegno|