Plasticity-based design and static performance of UT-type joint for construction error adaptation

To solve the problem of insufficient development of prefabricated rectangular hollow section (RHS) beam-column joints, a new type of prefabricated joint (UT-type joint) is proposed in this paper. The problem of construction error is effectively solved using a unique structural design, and the plastic energy dissipation section is introduced based on the concept of plastic controllability. This research mainly includes three aspects: (1) a new type of beam-column loading test device is designed, and a static loading test of the UT-type joint is carried out to evaluate the static performance of the joint; (2) through finite element simulation, the static performances of UT-type joints and traditional RHS joints are compared; and (3) based on the existing specifications and simulation results, a simplified design method for UT-type joints is proposed. The main research findings are as follows: (1) the static bearing capacity of the UT-type joint is slightly lower than that of the traditional RHS joint, with a maximum decrease of 15.4%; and (2) compared with the traditional RHS joint, the UT-type joints exhibit better plastic controllability, lower axial force sensitivity, and construction error adjustment ability (± 5 mm adjustment by adjusting the sleeve). These advantages give UT-type nodes a good application prospect.