Numerically Efficient Three-Dimensional Model for Non-Linear Finite Element Analysis of Reinforced Concrete...

Area of Science:

• Civil Engineering
• Computational Mechanics
• Materials Science

Background:

• Non-linear finite element analysis (NLFEA) is crucial for reinforced concrete (RC) structures.
• Accurate constitutive models are needed for NLFEA, particularly considering concrete-steel bond effects.
• The tension stiffening (TS) effect significantly influences RC structure deflections but is often simplified or omitted.

Purpose of the Study:

• To propose a new constitutive hypoelastic-brittle model for concrete within NLFEA.
• To develop an alternative method for incorporating the tension stiffening (TS) effect by modifying the reinforcing steel model.
• To validate the proposed models for predicting the load capacity and deformability of RC structures.

Main Methods:

• Development of a new hypoelastic-brittle constitutive model for concrete.
• Implementation of a generalized material model for reinforcing steel to account for TS.
• Utilizing the Abaqus finite element software with a UMAT user-defined subroutine.
• Verification and validation through four case studies, including material point tests and beam analyses.

Main Results:

• The proposed constitutive model and TS approach accurately predict structural behavior.
• The method effectively captures the influence of concrete-steel bond on structural response.
• Validated results show good agreement with experimental and other numerical outcomes.
• Accurate prediction of both load capacity and structural deformability was achieved.

Conclusions:

• The developed NLFEA approach provides a precise description of TS.
• The proposed models offer a reliable and efficient engineering tool for RC structure analysis.
• This method enhances the prediction accuracy of structural deformability and load capacity.