STUDY ON SEISMIC BEHAVIOR MODELING AND KEY PARAMETERS OF THE UNSYMMETRICAL HYBRID CONNECTIONS

Unsymmetrical hybrid connection is a post-tensioned dry connection with damping. The finite-element analysis program DRAIN_2DX was used to simulate the seismic-resistance performance under reverse cyclic loading. Results of the finite-element analysis showed that the hysteretic curves were unsymmetrical，plumper with better energy-dissipation under positive loading，while thinner with worse energy-dissipation under negative loading，and that the hysteretic curves showed thesshape which gradually became bow shape，and that the increase of initial compressed stress would lead to the reduction of ductility and residual deformation，and that the increase of the area of the mild steel bars could improve the energy-dissipation ability，however increased the residual deformation. The area ratio and the initial unbonded length of mild steel bars，and the effective stress of PT tendons were studied，some useful design advice was brought forward.