Formulation of an efficient shear-flexure interaction model for planar reinforced concrete walls: Fid-Bau Portal

Formulation of an efficient shear-flexure interaction model for planar reinforced concrete walls

Massone, Leonardo M. / López, Carlos N. / Kolozvari, Kristijan

Highlights • Shear-flexure interaction captures more accurately the response of slender and squat walls. • Calibration of horizontal expansion improves the response of squat walls. • Calibration of horizontal expansion removes the additional degree of freedom reducing the analysis runtime. • The Efficient-Shear-Flexure-Interaction (E-SFI) model is an accurate and efficient formulation for walls.

Abstract A research was conducted to develop a macroscopic modeling approach that integrates axial, flexure, and shear interaction under cyclic loading conditions to obtain reliable predictions of the nonlinear response of reinforced concrete (RC) structural walls. The model, named as Efficient-Shear-Flexure-Interaction (E-SFI), is intended to provide accurate results for squat, medium-rise, and slender planar walls, with a computationally efficient formulation that can be used under generalized conditions. The E-SFI model, which is based on the Shear-Flexure Interaction Multiple-Vertical-Line-Element-Model (SFI-MVLEM), incorporates a two-dimensional RC panel behavior described with a fixed-crack-angle approach. The novel formulation removes the internal degree of freedom per RC panel element of the SFI-MVLEM by incorporating a calibrated expression to compute the horizontal normal strain ( $ε_{x}$ ), and therefore removing the assumption of zero resultant horizontal stress ( $σ_{x} = 0$ ) to increase the range of applicability of the model. Three RC wall specimen tests were selected to calibrate and validate the E-SFI model, as well as to prove the model efficiency, including a slender wall (shear span-to-depth ratio of 3.0), a medium-rise wall (shear span-to-depth ratio of 1.5), and a squat wall (shear span-to-depth ratio of 0.63). Analytical model results reveal the ability of the model to accurately reproduce the hysteretic response for all considered cases, with an important reduction in the runtime and an improved current tangent convergence rate compared with the SFI-MVLEM.