Numerical investigations on mechanical behavior of friction damped post-tensioned steel connections

The post-tensioned energy dissipating connection for steel frames has drawn considerable attention because of its good seismic performance. Friction mechanisms, such as friction damped post-tensioned (FDPT) steel connections, are typically used to improve energy dissipating capacity. Many researchers have investigated the seismic behavior of FDPT through numerical or experimental method. Prior studies have indicated that the analysis by elaborate FE models is very time-consuming. To overcome this disadvantage, a friction element was first proposed based on general FE code and then incorporated into a simplified numerical model of PT connection to consider the effects of friction. The accuracy of results derived by this model was validated against prior experimental investigations. The effects of friction force value and initial PT force seismic behavior of FDPT connection was investigated. The geometric and material nonlinearities and strands can be considered in the modeling. A planar steel frame structure was established, and hysteretic analysis was conducted in the end. Results indicated the computational cost can be reduced significantly by this model.