An advanced FE analysis of PSC shell structures incorporating tendon-induced deformation-dependent loads

In the analysis of prestressed concrete (PSC) structures, the nonconservativeness of the prestressing effect has been often neglected or treated in a simple manner. However, the tendon-induced deformation-dependent loads can disturb the fast convergence to the correct solution and sometimes make the solution diverge without elegant formulations, when the PSC structures undergo large deformations. To solve this problem, an advanced numerical analysis procedure is proposed for the PSC shell structures. Geometrically nonlinear finite element analysis is performed for the tendon-induced equivalent loads that are considered here as the follower loads. In many cases, prestressing tendons are arbitrarily arranged inside a concrete structure with some eccentricities with respect to the mid-surface. In this study, therefore, combined effects of the improved displacement field of the shell elements with the eccentrically applied follower loads are investigated and consistently derived with the form of the load correction stiffness matrix (LCSM). Numerical examples show that the proposed procedures can correctly predict the geometrically nonlinear response of the PSC shell structures up to large deformations with the apparent contribution of the derived LCSM and exhibit much faster convergence behavior.