Development of Ductile Steel Knee Brace Member with Steel Shapes and Mechanical Joints

2015 Fiscal Year Final Research Report

• Project/Area Number: 25420568
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Building structures/Materials
• Research Institution: Chiba University
• Principal Investigator: Harada Yukihiro 千葉大学, 工学(系)研究科(研究院), 教授 (10272791)
• Co-Investigator(Renkei-kenkyūsha): HONMA SAYURI 石川工業高等専門学校, 助教 (60772499)
• Project Period (FY): 2013-04-01 – 2016-03-31
• Keywords: 方杖 / 耐震改修 / 鉄骨造建物 / せん断降伏

Outline of Final Research Achievements

A new ductile knee brace with a built-in comb-shaped damper for seismic retrofitting is proposed in the present study. The proposed 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-yielding struts in the comb-shaped web. Cyclic loading tests of component and subassemblage specimens were conducted to investigate cyclic behavior of the knee brace. The test results show that the knee brace exhibited a sufficient deformation capacity, i.e., the knee brace worked as a seismic damper. The strength of the overall knee brace member can be estimated well by a simple mechanical model. The cyclic behavior of the subassemblage specimens can be simulated via a frame analysis with a tri-linear axial load-deformation model of the knee brace member. It is also shown that the experimental low cycle fatigue lives of the knee braces can be predicted with the fatigue curve of the steel.

Free Research Field

建築鋼構造