Fracture Model for PT Flat Plate Connections under Seismic Loading

Post-tensioned (PT) flat plate frames are commonly used to support gravity load in connections in high seismic regions. But test results of many studies indicated that PT flat plate connections were possessed of later-resisting capacity for lateral load though this capacity is not enough to be used by itself in high seismic regions. So this study evaluated the cyclic behavior of PT flat plate connections and developed an analytical model for predicting nonlinear behavior of those to estimate the seismic performance of PT flat plate frames accurately. For this purpose, the test results of static pushover test and shaking table test of 2 story PT flat plate frame were used to evaluate the characters of failure mode for PT flat plate connections and to compare with analysis results. The test results indicated two failure modes which are classified the shear failure mode or the moment failure mode as for shear strength of PT connections to resist lateral loads acted on the specimens. So the analytical model was designed to consider these failure modes of PT connections and the results of comparing with test results predict the nonlinear behavior of PT connections.