Experimental and numerical investigation into the fire performance of glulam bolted beam-to-column connections under coupled moment and shear force

The fire resistance of connection plays a crucial role in the fire performance of timber structures. During the past three decades, massive real-scale fire tests were performed on timber connections to analyse the mechanical behavior of connections under fire situation. Although different loading scenarios was considered in previous timber connection tests, little research focused on the beam-to-column connections loaded with a combination of stress caused by bending moment and shear force. For post and beam structures, when structures undergo large inter-story drift, the interforce at the connection includes not only shear force but also bending moment. In this study, real-scale tests are carried out on bolted beam-to-column connections loaded with coupled bending moment and shear force under normal temperature and ISO fire exposure. Three-dimensional numerical model of the bolted beam-to-column connections are developed and validated by experimental results. The model is capable of simulating the evolution of temperature in the connections as well as their mechanical behavior. The comparison of the rotation-time curve between experimental data and thermo-mechanical model shows comparable tendency. The experiments and numerical models in this study can enrich existed experimental data of glulam connections and can be used to calibrate the design approach for bolted beam-to-column connections under fire exposure.