A finite element model to simulate long-term behavior of prestressed concrete girders

The development of a finite element model for time-dependent analysis of bonded prestressed concrete girders at service conditions is presented. The effects of creep and shrinkage of concrete and relaxation of steel tendons are taken into account. The concrete creep is modeled based on the Dirichlet series creep compliance with efficiency in simulating the stress history. In addition, the interaction between different time-dependent effects is fully considered in the numerical procedure. The numerical method is formulated based on the layered Euler-Bernoulli beam theory. In the constructed incremental equilibrium equations, the equivalent nodal load increments consist of four components contributed by external loads, concrete creep, concrete shrinkage and tendon relaxation, while the stiffness matrix is composed of the material and geometric stiffness matrices. Numerical examples show that the proposed model can well predict the long-term behavior of prestressed concrete beams, and that the time-dependent effects have important influence on the structural behavior.

[1]  M. Bradford,et al.  Flexural time-dependent cracking and post-cracking behaviour of FRP strengthened concrete beams , 2012 .

[2]  Tiejiong Lou,et al.  Nonlinear and time-dependent analysis of continuous unbonded prestressed concrete beams , 2013 .

[3]  Mete A. Sozen,et al.  A Study of Stress Relaxation in Prestressing Reinforcement , 1964 .

[4]  Zdeněk P. Bažant,et al.  Prediction of concrete creep and shrinkage: past, present and future , 2001 .

[5]  S. Lopes,et al.  Flexural Response of Continuous Concrete Beams Prestressed with External Tendons , 2013 .

[6]  O. C. Zienkiewicz,et al.  Some creep effects in stress analysis with particular reference to concrete pressure vessels , 1966 .

[8]  Xuhui Bu,et al.  Model-Free Adaptive Control Algorithm with Data Dropout Compensation , 2012 .

[9]  Hyo-Gyoung Kwak,et al.  Numerical analysis of time-dependent behavior of pre-cast pre-stressed concrete girder bridges , 2002 .

[10]  S. Lopes,et al.  Importance of a rigorous evaluation of the cracking moment in RC beams and slabs , 2012 .

[11]  Amin Ghali,et al.  Concrete Structures: Stresses and Deformations , 1994 .

[12]  Zdenek P. Bazant,et al.  COMPARISON OF APPROXIMATE LINEAR METHODS FOR CONCRETE CREEP. , 1973 .

[13]  Anthony Duncan Jefferson,et al.  Time-dependent behaviour of widened reinforced concrete under-bridge , 1998 .

[14]  Francis T. K. Au,et al.  Accurate time-dependent analysis of concrete bridges considering concrete creep, concrete shrinkage and cable relaxation , 2011 .

[15]  P. Valent,et al.  EFFECTS OF LONG-TIME LOADS ON PRESTRESSED CONCRETE BEAMS. , 1964 .

[16]  J. Rodríguez-Gutiérrez,et al.  Short- and Long-Term Deflections in Reinforced, Prestressed, and Composite Concrete Beams , 2007 .