Aliaari and Memari 2007
The authors examined an infill wall fuse system with the goal in mind to prevent damage to the columns and infill walls. This device is known as a SIWIS. Sacrificial disks made of steel, concrete, and timber were tested and compared to determine which was most adequate as a fuse element.
System Concept
Structural fuse elements are located in the gaps between the infill walls and the frame structure. As a lateral load is applied, the fuses are engaged, and are designed to yield before the frame or infill wall yields. The yielding of the fuse disks acts as an energy-dissipating mechanism. A punching rod is placed next to the disks as a rigid element to help fail the fuse.
Experimental Study, Results, and Discussion
Three structures were tested in this study: a two-bay 3-story frame of bare steel, infilled brace frame, and pinned frame with the SIWIS. Component tests were also conducted to determine the failure stresses and strains of disks made of concrete, steel, and lumber. A lateral load in-plane strength test was also conducted on a single-layer masonry wall to determine the in-plane strength of the wall. This was done so that the fuse could be designed to fail before the wall.
The three disk types were compared with disks of similar capacity to determine the relative stiffness of the potential energy dissipaters. It was found that the steel and concrete disks were less ductile than the lumber disk. The lumber disk experience less of a drop in resisting load after the peak load. These results led to the use of lumber disks in the two-bay 3-story frame test.
The test frame was built as a 1-4 scale model with pinned beam to column and column to column connections. Testing occurred on a bare steel frame, an infill frame with diagonal bracing, and an infill frame with SIWIS elements. It was found that if an SIWIS (timber disk) fails at the point of load application (the third story), the resistance of the system drops to zero since there is no in-plane resistance. The punching rod can punch through and fail the disk. The frame fails without interaction with the masonry wall panels. This experiment showed that having properly designed SIWIS can produce interaction between the masonry infill wall and a frame, increasing the in-plane strength of the system.
Reference
Aliaari, M. and Memari A.M. (2007). "Experimental Evaluation of a Sacrificial Seismic Fuse Device for Masonry Infill Walls," Journal of Architectural Engineering. 13.2, pp. 111-125.