The technology designs a modular friction stir welding tool holder. This welding tool holder integrates a variety of functions, including constant pressure welding, temperature monitoring, removable FSW tool design,can be clamped to an existing CNCmachine. The advantage is that it can realize the function of automatic exchange for friction stir weldingCNC milling in one machine. Breaking through the previous friction stir welding, you need to buy a friction stir welding machine, which is expensive to obtain.

Conventional buildings use beambrace members to dissipate seismic energy. However, these members may cause residual deformation of buildings under large earthquakes, which affects the building seismic performanceincreases the difficulty of reuse after earthquakes. Therefore, a novel earthquake-resisting member "Dual-Core Self-Centering Brace, DC-SCB” was developed. The DC-SCB uses tendons to provide the elastic restoring forcea friction devicesteel bars to provide energy dissipation so that the building can return to the original position after major earthquakes. The DC-SCB significantly reduces the residual deformationrepair cost of the building after earthquakes, also reducing the large lateral displacementcollapse of the building.