Ozaki, Kawai, Kanno, and Hanya, 2012
Self centering rocking frames were tested and compared to free rocking braced frame systems using both a static load testing and shake table tests, and data were collected to indicate the effectiveness of each of the systems. Four structures were tested: one system equipped with a fuse function (HDF) with a 5kN yield strength, one system equipped with a fuse function (HDF) with a 10 kN yield strength, one with elastic fasteners, and one free rocking system. They were each subjected to a shake table test after performing a static load test. Static load testing was first used on the HDF1 structure by applying monotonic tensile and cyclical loading. Shake table tests were performed on the four structures using data from El Centro-NS and Kobe-NS. The shake table tests used a range from a 40% to 120% scale of the two earthquakes to test the structures.
System Concept
Hold downs equipped with a fuse function included a steel plate with slits cut into it to act as the fuse. The fuses were shaped into a butterfly pattern. A pair of fuse steel plates were welded to a U shaped steel channel. This structure was then inserted into a steel channel of a steel wall with self drilling screws and connected to an anchor bolt.
Analysis, Results, and Discussion
It was found that the system dissipated energy through plastic deformation of the HDF such that the building's rocking behavior would dissipate the seismic energy. Structures with an HDF demonstrated the smallest base shear, and uplift deformation.
Reference
Ozaki, F., Kawai, Y., Kanno, R., Hanya, K. (2012). “Damage-Control Systems Using Replaceable Energy-Dissipating Steel Fuses for Cold-Formed Steel Structures: Seismic Behavior by Shake Table Tests,” Journal of Structural Engineering, 139. 5, pp. 14.