Open AccessNonlinear Finite Element Analysis of Reinforced Concrete Beam-Column Connection with Interface Elements under Cyclic Loading
Author(s) -
Abuzaid Esraa Khudhair Mohsin
Publication year - 2020
Publication title -
iop conference series. materials science and engineering
Language(s) - English
Resource type - Journals
eISSN - 1757-899X
pISSN - 1757-8981
DOI - 10.1088/1757-899x/745/1/012128
Subject(s) - structural engineering , finite element method , nonlinear system , materials science , stiffening , virtual work , cracking , tension (geology) , beam (structure) , ultimate tensile strength , composite material , engineering , physics , quantum mechanics
To study the nonlinear response of corner beam-column junctions with inclusion of the effect of construction joint between the column and the beam cast at different times and subjected to cyclic and repeated loads, a computer program of three dimensional nonlinear finite element analysis, written by Al-Shaarbaf[1], (P3DNFEA)has been extended to account for the effect of construction joints on the behavior and to deal with concrete behavior under cyclic loads. The 20-node isoperimetric brick elements have been used to model the concrete, while the reinforcing bars are modeled as axial members embedded within the brick elements. A nonlinear cyclic behavior model for concrete is developed in uniaxial and multiaxial states of stress. Also, a nonlinear cyclic behavior model for reinforcing bars is presented. In completion, the behavior of concrete under cyclic loads is simulated by an elasto-plastic work hardening model followed by a perfectly plastic response. In tension, affixed smeared crack modeled has been used to simulate the behavior of concrete with a tension-stiffening model to represent the retained post-cracking tensile stresses in concrete. Closing and reopening of cracks during cyclic loading has been taken into consideration. The nonlinear equations of equilibrium have been saved using an incremental-iterative technique based on the modified Newton-Raphson method. The convergence of the solution was controlled by a force convergence criterion. The numerical integration has been conducted by using 27-point Gaussian rule. To represent the shear transfer between two concretes cast at different times, 20-noded interface layer brick elements are used with Fronteddu’s and Millard’s models to represent the aggregate interlock and the dowel stiffness, respectively. Comparison between the results obtained from the finite elements and the available experimental results is made for a corner beam-column junction with inclusion of the effect of a construction joint. Good agreement is obtained. The maximum difference in ultimate load is 3.9%. A parametric study dealing with construction joint is presented by taking various conditions of the junction. These include the axial load on the column, strength of concrete in the second cast.