Lateral performance of mortise-tenon jointed frames in multi-story traditional heavy timber structures: Mechanism and quantification

•Lateral resistance from the columns and mortise-tenon joints was isolated and obtained by experiment.•Lateral load-resisting mechanism of mortise-tenon jointed timber frames was quantified.•Characterized models were proposed for the lateral resistance from the columns and joints.•The influence of column height and diameter on the lateral load-resisting mechanism of the frames was studied. This study isolated and quantified the lateral load-resisting mechanism of mortise-tenon jointed frames in multi-story traditional heavy timber structures. By decomposing the lateral performance of the mortise-tenon jointed frames, three rocking frame specimens and a moment-resisting frame specimen were half-scaled designed. Lateral resistance from timber columns and mortise-tenon joints was directly obtained by reversed cyclic loading tests, respectively, and was compared to quantify the mechanism of the mortise-tenon jointed frames in different stories. Characterized models were proposed for the lateral resistance from the columns and joints, respectively. A model-based parametric study was further conducted to indicate the influence of the column height and diameter on the mechanism of the mortise-tenon jointed frames. Test results showed the columns dominated both in the lateral load-resisting capacity and energy dissipation capacity of the frames at small drift, and the columns still contributed over 50% of those capacities before a drift of 10% with the increase of loading amplitude. The characterized models well captured the evolution features of the load–displacement curves of the tested specimens. The parametric study indicated that by increasing 30% of the column height, the lateral load contribution of the mortise-tenon joints ranged from 60% to 90% at a drift of 12%. Moreover, a decrease of 30% in the column diameter led to a significant drop in the load-resisting capacity and deformability of the columns, making the mortise-tenon joints dominate in the lateral capacity of the frames after a drift of 8%.