Staged Failure Mechanism of Aged RC Beam-Columns Subjected to Corrosion Loads Using Simplified Nonlinear Finite Element Model

An analysis approach to simulate the staged failure mechanism of corrosion-affected beam-column subjected to ultimate or seismic load using a simplified, non-linear, finite element model is proposed. The instantaneous axial and flexural rigidities at the sectional level are transferred to the element level, establishing the instantaneous structure stiffness at each load step. The approach efficiency and accuracy are verified through comparison with available experimental and analytical results. The proposed approach is numerically stable in all studied cases. It is found that the staged failure mechanism of the columns subjected to quasi-static load and cyclic load up to failure can be simulated with high accuracy. It is also found that corrosion-induced damage results in a large drop of the column load and displacement capacities, and a large shrinkage in the hysteretic relationship, which indicates similar drop in the energy absorption capacities of the beam-columns.