3D analysis of solid reinforced concrete beams subjected to combined load of bending, torsion and shear

摘要

This paper presents a comparison between experimental and an in house 3-D finite element analysis results of three reinforced concrete solid beams subjected to combined loadings of bending, shear and torsion. The finite element program adopted was based on a 20 node isoparametric element. A non-linear elastic isotropic model, proposed by Kotsovos, was used to model concrete behaviour, while steel was modelled as an embedded element exhibiting elastic-perfectly plastic response. Allowance was made for shear retention and for tension stiffening in concrete after cracking. Only fixed direction, smeared cracking modelling was adopted. The beam dimensions were 300×300mm cross section, 3800mm length. Experimental results were compared with the non-linear predictions. The comparison was judged by load displacement relationship, steel strain, and load and mode of failure. Good agreement was observed between predicted ultimate and experimentally measured loads. It was concluded that the present program can confidently be used to predict the behaviour and failure load of reinforced concrete solid beams subjected to combined load of bending, torsion and shear.