Investigating the Cyclic Behaviour of Post-tensioned Steel Connections by Changing the Diameter and Arranging the Strands

Failures of steel frames during Northridge 1994 earthquake prompted researchers to improve the behavior of beam-column connections where most of the fractures occurred. therefore, various details have been proposed for moment connections. post-tensioned connection is one of the new connections proposed by researchers. In this study, the numerical modeling of the post-tensioned connection was performed using Abaqus finite element software. In addition to verifying the accuracy of the modeling with the experimental results, 4 samples of the connection were modeled and Was investigated the effect of some parameters on the connection behavior under cyclic loading. In the range of models of this paper, the results show that increasing the strand diameter by fixed post-tensioning force Increases the Flexural strength and power in the lateral force bearing. Also, the increasing the strand diameter by fixed post-tensioning force does not affect the connection initial stiffness. In addition, increasing the number of strands from 4 to 6, leads to an Increase connection power in the lateral force bearing to 11.6% and an increase in Energy dissipation to 2.4%. Also, Increasing the number of strands will increase the flexural capacity and decrease the maximum force of each strand. the use of less strand with Equivalent diameter and Equivalent post tensioning force, and changing the strand spacing from the center of gravity of the beam does not affect the behavior of the connection