Seismic performance and design methods of self-reset artificial controllable plastic hinge using SMA bars

To improve the repairability of prefabricated buildings, reduce the post-earthquake repair workload, and prolong the service life of prefabricated buildings, this paper designed a new type of self-reset artificial controllable plastic hinge (SACPH) for assembled beam-column joint, which is made of Shape Memory Alloy (SMA). A theoretical design method of the SACPH joint was established. The hysteretic performance of eleven assembled joints with different design parameters, such as different diameters, lengths and material properties of SMA, were studied by finite element software based on the experimental verification model. The results showed that the maximum residual deformation of SACPH was only 2 %. The damage of SACPH mainly concentrated on the weak area of the SMA bar. The average yield and peak loads of the SACPH specimen were 20.95 % and 17.39 % lower respectively, than those of the cast-in-place frame. When the amount of steel bars used in SACPH was 20 % of the cast-in-place specimen, the bearing capacity could reach about 80 % of the latter. Increasing the diameter of the SMA bar and reducing its the length could improve the bearing capacity and self-reset ability of SACPH joints. The applicable range of the diameter and the length of the energy dissipation bars were 14 mm to 22 mm and 225 mm to 275 mm, respectively. In addition, a theoretical model in predicting the bearing capacity and displacement of SACPH joints when they yield are established, and the theoretical results agreed well with the simulation results.