Nonlinear Numerical Modeling of Prestressed Concrete Beams with Variable Sectional Stiffness

Abstract

 

This paper presents a nonlinear finite element formulation for the analysis of prestressed concrete beams under different loading conditions. Particular attention is devoted to the modeling of prestressing effects, incorporated into the sectional stiffness matrix through an incremental variable-stiffness approach. The formulation also accounts for material nonlinearity and second-order effects using two-node beam elements combined with Simpson’s integration scheme. The proposed model is based on the principle of virtual work and includes constitutive modeling of concrete and prestressing steel materials. Numerical predictions were validated against experimental results obtained from prestressed concrete beams. Good agreement was observed between numerical and experimental results in terms of load-deflection response, nonlinear behavior, and overall structural performance.

The results demonstrate the accuracy and reliability of the developed formulation, showing its effectiveness as a numerical tool for the analysis and design of prestressed concrete beams.