Development of Ductile Steel Knee-Brace Member with Built-in Comb-Shaped Damper

Estimation Method on Hysteresis Characteristics of Subassemblage with Ductile Knee-Brace Member

“…The cyclic loading tests of the ductile knee braces were conducted with five different specimens (Table . 1, Fig. 3) [1], and the specimen denoted H2-60 is the ductile knee brace used in subassembrage test.…”

“…The loading was displacement-controlled with the overall frame displacement f δ a under the beam end load b Q. the overall frame displacement f δ a , it is shown as follows, the displacement amplitudes were 12.5, 25, 37.5, 50, and 62.5 mm. Here, the skeleton curve of the N-δ a relationship under positive loading was modeled as a single spring element with the tri-linear axial force-deformation relationship described previously [4]. The yield strength N y and full piastic strength N p of the ductile knee brace were calculated from this short coulmn model, and the full piastic moment f M p of locally-bent flange part was modeled with the single spring element.…”

“…10. Here, N y is the yield strength of the ductile knee brace [1]. If other members do not plastify at this load b Q, the ductile knee brace plastifies earliest.…”

“…In order to make the knee brace member absorb more seismic energy in the overall frame, the authors proposed a ductile knee brace member with a built-in-comb-shaped damper (Fig. 1) [1]; such an comb-shaped steel device has been applied to seismic shear walls [2] or X-bracings [3], but not to knee braces. The ductile knee brace is composed of a wide-flange member with multiple slot holes in its web plate, which is designed to plastify earlier at shear-yield struts in the comb-shaped web (Fig.…”