Koji Hanya

Damage-Control Systems Using Replaceable Energy-Dissipating Steel Fuses for Cold-Formed Steel Structures: Seismic Behavior by Shake Table Tests

AbstractA system that controls the rocking behavior of multistory shear walls is proposed as an innovative damage-control system for cold-formed steel structures. In this system, we have developed a new hold-down equipped with a fuse function (HDF) that controls the rocking behavior and is placed on the foundation of multistory shear walls. The HDF contributes to reducing damage to both structural and nonstructural members in cold-formed steel framed buildings, dissipating seismic input energy in the event of a large earthquake. The present paper describes the shake table tests performed using one-story, one-span, real-size specimens to investigate the fundamental behavior of the developed system. By using shake table tests in which the type of hold-down and the magnitude of input ground motion were varied as parameters, it was clarified that the plasticization of HDFs could reduce the base shear of specimens and that the energy dissipation by the HDFs could subdue the uplift deformation of the specimens....

Cyclic Behavior of Corrugated Steel Shear Diaphragms with End Failure

AbstractLight-gauge steel frames with load-bearing walls have become one option in robust structural systems for low-rise buildings. This structural system is often used in steel-framed houses and in typical load-bearing walls consisting of a light-gauge steel frame with plywood and gypsum boards fastened by self-drilling screws. These load-bearing walls dissipate seismic energy mainly through local bearing failure of the cladding boards at the screw connections, exhibiting significant slip and pinching behavior. This behavior tends to decrease the energy dissipation capacity of the bearing walls because of the small areas of the cyclic hysteresis loops. To improve the energy dissipation capacity, corrugated shear diaphragms failing in the end-failure mode were studied by conducting monotonic and cyclic loading tests of simple shear panels under ideal boundary conditions with pure shear loading. A full-scale load-bearing wall using corrugated steel sheets with end failure was also studied under cyclic loa...

Amplitude Temperature of Steel Claddings Exposed to Solar Radiation

Steel claddings such as a long spanned roof have been damaged by metal fatigue affected by wind load or thermal load. To reduce damage of steel claddings, it is necessary for design and construction to consider metal fatigue influence. This paper shows a basic data for steel claddings to evaluate fatigue damage caused by cyclic thermal expansion exposed to solar radiation. Specimens are fabricated which specification are steel sidings and steel sandwich panels, and surface temperatures of specimens are measured throughout the year. Then, amplitude temperatures and their cyclic numbers are evaluated.