Finite Element Mesh Size Effect on Deformation Predictions of Reinforced Concrete Bridge Girder

Abstract

Present research was dedicated to investigation of finite element size effect on deformation predictions of reinforced concrete bending members. Experimental beams have been modelled by commercial finite element software ATENA, using two main approaches for simulating tension-stiffening: stress-crack width (fracture mechanics approach) and average stress-average strain relationships. The latter approach uses the ultimate strain adjusted according to the finite element size. It was shown that the modelled post-cracking behaviour of the beams is dependent on the finite element mesh size. To reduce this effect, a simple formula has been proposed for adjusting the length of the descending branch of the constitutive relationship. Post-cracking behaviour of a reinforced concrete bridge girder has been investigated assuming different finite element mesh sizes. The analysis has shown that the proposed technique allows reducing the dependence of calculation results on the finite element size.