Numerical modeling of a bolted beam-column connection subjected to cyclic loading

Abstract

In precast concrete systems, connections play a crucial role in ensuring structural continuity between elements and contributing to the overall stability of the structure. Among various types, semi-rigid bolted beam-to-column connections are commonly used to reduce on-site construction time. Additionally, they provide enhanced energy dissipation under seismic loading compared to cast-in-place connections. This study developed and validated a nonlinear numerical model in DIANA® software to simulate the behavior of a bolted beam-to-column connection under monotonic and cyclic loading. An analytical model was also proposed to estimate the secant stiffness of the connection. The numerical model was calibrated using experimental data available in the literature, showing a maximum error of 3% in predicting ultimate strength and 30% in energy dissipation capacity. Moreover, the model accurately represented the stiffness, cracking pattern, and global behavior of the connection. A parametric analysis was conducted to assess the influence of concrete strength, bolt diameter, and bolt steel grade on the connection performance. The comparison between cyclic and monotonic loading indicated low stiffness degradation up to the yielding of the bolts. The proposed analytical model yielded a stiffness ratio (numerical-to-analytical) of 1.00 with a coefficient of variation of 4.54%, confirming its applicability for estimating the stiffness of bolted connections.