Numerical analysis of the performance of beam-column connection using hidden steel corbel in precast concrete structures

Abstract Precast concrete construction has advantages over conventional in situ methods, including short construction time and improved quality control. The performance of precast construction heavily relies on its connections, whose lack of knowledge can lead to oversimplified and conservative designs. This study uses a FEM-based numerical model to evaluate the performance of a beam-to-column connection with a double-sided steel hidden connector and top continuous bars. Experimental and analytical studies validated this model, considering moment-rotation diagrams. The connection was classified as a medium-strength semi-rigid connection, similar to the reference study. The moment-rotation diagram closely aligned with experimental results, with errors ranging from 5% to 13% at the yield of the top bars. The discrepancies between the results may stem from simplifications in the simulation, e.g., symmetry assumptions, constitutive models, and interactions. A parametric analysis was conducted considering (i) the yield stress of the connector, (ii) the steel reinforcement ratio of the top bars, (iii) the presence of stirrups over the connector, and (iv) the addition of welded bars to the hidden corbel. Increasing the yield stress of the connector and the reinforcement ratio of the top bars, as well as adding stirrups over the connector, enhanced the connection properties. The use of welded bars to the corbel did not affect the results. The reinforcement ratio had the most significant impact. In conclusion, the proposed numerical model provided an efficient analysis of the beam-to-column connection and could contribute to refine the current designs.