Title:
ACI PRC-447.2-25: Nonlinear Finite Element Analysis of Reinforced Concrete Beams, Columns, and Beam-Column Joints—Guide
Author(s):
ACI Committee 447
Publication:
Technical Documents
Volume:
Issue:
Appears on pages(s):
41
Keywords:
DOI:
Date:
2/27/2026
Abstract:
Using finite element (FE) analysis to model the nonlinear behavior of reinforced concrete can range from relatively simple, phenomenological approaches to highly complex, micromechanics-based models. The choice of approach depends on the desired accuracy, the scale of the analysis, expertise of the analyst, and computational resources. Plastic hinge models, typically used in pushover or nonlinear time-history analyses for global response prediction introduce basic nonlinearity for line-type elements but often fall short in numerous applications, including evaluating the performance or safety of structures; analyzing deep beams and disturbed regions; assessing distress in existing structures; and predicting crack patterns, crack widths, and deflections. In these cases, two-dimensional (2-D) or three-dimensional (3-D) continuum FE methods offer greater advantages. This guide focuses on nonlinear continuum FE methods, which introduce moderate to high levels of nonlinearity. Developed for practicing engineers, the guide aims to balance theory with practical applications, covering modeling approaches for key material aspects for cracked concrete (including mesh effects and regularization) and reinforcing steel (including stress-strain response, buckling, and bond slip), followed by practical guidance on continuum modeling of beams, columns, and beam-column joints.
Keywords:
assessment; bond slip; buckling; continuum; cracking; distress; finite element (FE); mesh; nonlinear; regularization.