Moment and energy dissipation capacities of post-tensioned precast concrete connections employing a friction device

This paper describes an analytical investigation into the design of unbonded post-tensioned (PT) precast concrete beam-column connections that employ a friction device. Design formulas related to the moment capacities, hysteretic energy dissipation capacities, and self-centering capabilities of the PT connections are developed in normalized form. The validation of the design formulas and the effect of normalized parameters such as friction force, initial post-tensioning force and the location of the friction device on the moment and energy dissipation capacities are investigated. A design procedure to achieve desired design moment and energy dissipation capacities for the PT connections is also developed using the design formulas. Contour plots for the linear limit moment and hysteretic energy dissipation ratio are provided for determining the required values of the normalized parameters. The investigation is based on the analytical responses from a nonlinear section analysis method for a number of PT connections with various sets of normalized parameters. The results confirm the adequacy of the design formulas and design procedure.