Title: Modelling of Stirrup Confinement Effects in RC Layered Beam Finite Elements Using a 3D Yield Criterion and Transversal Equilibrium Constraints

Author(s): Péter Zoltán Berke / Thierry Jacques Massart

Publication: IJCSM

Volume: 12

Issue:

Appears on pages(s):

Keywords: reinforced concrete confinement, stirrups, layered beam model, transversal equilibrium constraint,multiaxial yield criterion

DOI:

Date: 7/26/2018

Abstract:
Apart from its recognized strengthening effect for shear loading, the presence of stirrups in reinforced concrete results in an increase of the ductility of structural members and in the capacity of reaching higher longitudinal compressive stress levels provided by transversal confinement. These effects are usually represented phenomenologically in fibre beam models by artificially increasing the compressive strength and the ultimate compressive strain of concrete. Two numerical formulations for layered beam descriptions accounting explicitly for transversal confinement are implemented and assessed in this contribution. The influence of stirrups is incorporated by means of a multi-dimensional yield surface for concrete, combined with equilibrium constraints for the transversal direction involving concrete and steel stirrups, and with a concrete ultimate strain dependent on the hydrostatic stress. This contribution focuses on the numerical formulations of both frameworks, and on their assessment against experimental results available in the literature.