Investigation on the Behavior of Posttensioned Energy Dissipation Connections under Fire Loading

Azin Al kajbaf¹ Nader Fanaie²

1) Mastership Student of Structural Engineering, Civil Engineering Department, K.N. Toosi University of Technology, Tehran, Iran, Email:
2) Assistant Professor, Civil Engineering Department, K.N. Toosi University of Technology, Tehran, Iran, Email:

Publication : The 4th International Congress On Civil Engineering, Architecture & Urban Development(4icsau.ir)
Abstract :
Posttensioned energy dissipation (PTED) connections are systems developed to be used in structures which are located in seismic prone areas. These structures reduce the earthquake damage by removing the residual drift and dissipating the seismic energy. Following an earthquake, one of the most probable scenarios is a fire event. Therefore, understanding the behavior of PTED connections, which their primary application is in seismic areas, is of significant importance. This paper presents an analytical study on the behavior of a PTED connection with bolted top-and-seat angles subjected to the fire loading. Finite element model of a PTED connection is developed and verified based on experimental results. Another experimental study is selected which includes a beam-to-column subassembly with web cleat joints subjected to the fire loading. This connection is also modeled using finite element analysis and is validated using experimental results. Since no experimental data is available for PTED connections under fire condition, this verified model is employed to make sure that the behavior of an angle connection at elevated temperature is modeled accurately. Afterwards, PTED connection model is subjected to the fire loading. The analysis is conducted assuming three cases of PTED connection with unprotected strands, with protected strands and without strands. Temperature-rotation curves are derived and compared. The results show that the behavior of a PTED connection with unprotected strands is not considerably different than that of a typical semi-rigid connection subjected to the fire. However, using fire protection coating for strands significantly reduces the connection rotation and therefore prevents the structural collapse.
Keywords : finite element modeling fire loading posttensioned strands PTED connection