Theoretical Analysis Model of a New Post-Tensioned, Unbonded, Prestressed Beam–Column Connection

To investigate the mechanical properties of a new post-tensioned, unbonded, prestressed beam–column connection—including its hysteresis behavior and energy dissipation capacity—a theoretical analysis was conducted. Calculation formulas for key points on the moment–curvature (M-θ) hysteresis curve, including the yield point, failure point, and unloading point, were derived. A theoretical model describing the M-θ relationship of the connection was established. The energy dissipation capacity, which is a critical mechanical property of such connections, was quantified through a derived formula for the energy dissipation coefficient, accompanied by a parametric analysis. The results show that increasing the area of energy dissipation reinforcement enhances the energy dissipation capacity of the connection. When the yield strength of the energy dissipation reinforcement equals the initial prestress of the tendons, the energy dissipation coefficient approaches 0.5. Considering the asymmetric reinforcement layout, a self-centering performance evaluation method—accounting for bending moments on both sides of the connection—is proposed. The conditions required to achieve self-centering behavior are derived. Finally, the proposed model is validated through a comparison with experimental results.