Extended fibre decomposition procedure for nonlinear analysis of reinforced concrete 3D frames

This paper presents an extended fibre decomposition procedure for the material and geometrical nonlinear analysis of reinforced concrete (R/C) three-dimensional (3D) frames. The nonlinear finite element model adopts a decomposition approach for the cross-section of the beam-column element to capture uniaxial behaviour of concrete and rebars. Filaments in section are extended over the beam-column finite element (FE) and create prismatic comparative body discretized by the brick FE, to capture shear and torsional nonlinear behaviour of concrete and rebars. Smeared crack model for concrete is assumed. Perfect bond-slip effect between concrete and rebars is assumed. The tension stiffness effect is indirectly implemented due to the direct iterative approach. Incremental step model of gravitational load level is applied. The proposed procedure saves CPU time and memory of the personal computer.