A fibre flexure–shear model for seismic analysis of RC‐framed structures

Abstract

SUMMARYWhile currently existing modelling approaches of reinforced concrete (RC) behaviour allow a reasonably accurate prediction of flexural response, the determination of its shear counterpart needs further developments. There are various modelling strategies in the literature able to predict the shear response and the shear-flexure coupling under monotonic loading conditions. However, very few are the reported models that have demonstrated successful results under cyclic loading, as in the seismic load case. These considerations lead to this research work focused on the development of a flexure-shear model for RC beam-column elements. A reliable constitutive model for cracked RC subjected to cyclic loading was implemented as bi-axial fibre constitutive model into a two-dimensional Timoshenko beam-column element. Aim of this research work is to arrive at the definition of a numerical model sufficiently accurate and, at the same time, computationally efficient, which will enable implementation within a finite element package for nonlinear dynamic analysis of existing non-seismically designed RC structures that are prone to shear-induced damage and collapse.

Seismic Response of Reinforced Concrete Columns

“…Few studies in the recent past have also addressed the issues of stiffness degradation and strength deterioration in the reinforced concrete elements dominated by shear or shearflexure behaviors. These studies represent advanced formulations for fiber-based element (Ceresa et al, 2007(Ceresa et al, , 2009Chao & Loh, 2007;Mullapudi & Ayoub, 2008, 2010Xu & Zhang, 2011;Zhang & Xu, 2010) and Macro-element model (Mergos & Kappos, 2008, 2010 and consider interaction between inelastic shear and nonlinear flexural behaviors with different conceptual backgrounds, solution strategies and implementation complexities. A state-of-art review is presented on fiber elements with focus on concentrated plastic-hinge type model that can be implemented in displacement-based finite element programs (Ceresa et al, 2007).…”

Nonlinear Analysis of Shear Critical Rc Members Using Current Fe Software

“…The results of the SE panels were numerically reproduced in literature using constitutive models based on the main concepts of the MCFT and its further extensions [40], [42], [13], [43]. The results obtained in this study with Vector2 are compared with the ones published by Stevens et al [40] and Palermo and Vecchio [42].…”

“…Authors such as Litton [5], Bazant and Oh [6], Cervenka [7], Vecchio and Collins [8], De Borst [9], Hsu [10] and Maekawa et al [11], have developed methods to determine the shear behaviour of RC, using diverse types of assumptions in the process. As defined in Ceresa et al [12] [13], in the framework of smeared crack theory for RC the following main models can be identified:…”

An Exact Shear Strain Approach for Rc Frame Elements With Axial-Shear Interaction

“…The Timoshenko beam theory provides a kinematic link between shear strains and transverse displacements of the beam axis. Hence, multi-axial constitutive models can be used at each individual fiber resulting in full axial-shear coupling [7,8,9,10,11,12,13]. However, the theory predicts a constant shear strain profile over the section, thus violating inter-fiber equilibrium.…”

“…The tangent stiffness matrix of the section is obtained taking variation of section forces with respect to section deformations: (9) where is the condensed, 2×2 material stiffness matrix, given as:…”