A COMBINED NONLINEAR ANALYTICAL MODEL OF PRESTRESSED CONCRETE STRUCTURES

In order to predict the nonlinear behavior of prestressed concrete structures, a combined model based on the fiber section is proposed. A bond element is developed to simulate the bond-slip behavior between prestressed tendons and concrete, and the fiber section-based bond element is utilized to model that between reinforcing bars and concrete. The contribution to structural damage due to the low cycle fatigue property of materials is also considered. The proposed model is illustrated by three tests of prestressed concrete frames. The results show that the model is able to carry out the strength degradation, stiffness degradation and pinch phenomenon of structures under the cyclic loading，which conclude the exact hysteretic curve. It can also evaluate the dynamic properties of prestressed concrete structures under earthquakes. Because of the advantages of less computational effect and better convergence, the model can be used for the nonlinear analysis of prestressed concrete structures.