Tendon Model for Nonlinear Analysis of Externally Prestressed Concrete Structures

Abstract

The present study describes a nonlinear analysis model developed for externally prestressed structures. This model is capable of simulating the slip of the tendon on the deviator and the friction at the interface of the tendon and deviator. Combing the model with concrete and reinforcing steel models, a computer program for material and geometric nonlinear analysis of externally prestressed concrete structures, based on the incremental load method, is developed. The numerical procedure can predict the responses of externally prestressed concrete structures throughout their prestressing transfer and service load history, such as elastic and plastic deformation, cracking, and damage patterns. Two examples are analyzed to verify its capability and efficiency. Analytical and experimental results show good agreement with each other. The comparison of the geometric linear and nonlinear analytical results demonstrates that the second-order effects, associated with the progressive change in eccentricity of the tendons with the increase of member deformation, can be reduced effectively by setting deviators. The second-order effects are negligible when the deviator or deviators are set.