Enhancement of multifiber beam elements in the case of reinforced concrete structures for taking into account the lateral confinement of concrete due to stirrup
Résumé
Many researches have been conducted in the structural engineering field in order to develop efficient numerical tools able to reproduce the complex nonlinear behavior of reinforced concrete structures. In the case of slender elements, enhanced beam models have been developed to try to introduce shear effects, but in these models, the transverse steel is sometimes taken into consideration with approximated manner or often not at all. However, as shown by some experimental tests, the amount of transverse reinforcement triggers significantly the behavior of beam elements, especially under cyclic loading. The present study adresses this problem by investigating solutions for an enhanced multifiber beam element, accounting for vertical stretching of the cross-section occurring due to the presence of stirrups. A timoshenko beam element with internal degrees of freedom and higher order interpolation functions is selected. Full 3D stresses and strains are obtained and the construction of the element and sectional stiffness matrices is detailed. The element presented hereafter is suitable for an arbitrary shape cross-section made of heterogeneous materials. Numerical applications on a plain concrete cantilever beam subjected to tension and bending tests respectively are presented. Moreover, as a first application, a dilation effect is added to the concrete fibers in order to highlight the role of transversal rebars. All the numerical results are confronted to the outcomes of stantard 3D finite element computations.
Origine : Fichiers produits par l'(les) auteur(s)
Loading...