A Study of Local Buckling in All-Metal BRBs

• Main Authors: Chia-Yuang Liu, 劉家源
• Other Authors: Keh- Chyuan Tsai
• Format: Others
• Language: zh-TW
• Published: 2007
• Online Access: http://ndltd.ncl.edu.tw/handle/65723674326450290275

碩士 === 國立臺灣大學 === 土木工程學研究所 === 95 === Key words: All Metal、Buckling Restrained Brace、Local Buckling、All Metal Buckling Restrained Brace、BRBs After lots of studies and tests in the laboratory, buckling restrained braces (BRBs) have played an important role in seismic building applications in recent years. However, in order to deal with the situation that the proportion of using steel in Taiwan is much less than foreign countries. Developing all-metal BRBs that can effectively prevent local buckling and save cost is necessary. The objectives of this study include: (1) developing the new type of all-metal BRB; (2) investigating the strength requirement for the confining steel rib intensity ; (3) sliming down the new type of all-metal BRB . Test results showed that the new type of all-metal BRB is feasible procedure to fabricate BRBs. Tests confirmed that the confinement requirements developed based on the compressive stiffness of the steel rib are not sufficient in the slim-lined BRBs. Based on the flexural mode, it is found that the required stiffness of the steel rib is a function of core steel plate width to thickness ratio (b/t) and width to confining rib height ratio (b/h). For example: if the brace core is made from ASTM A572 Grade 50 steel, the necessary steel rib a has to greater than 0.004424(b/h)3(b/t)b. In this formula, the requirement of steel rib is proportional to (1/h)3 . H200a18 and H175a30 are designed by same safety factor and they failed at the same time. H200a22 has the best performance in four specimens. This result shows that the design logic is not bad . On the other hand, preventing the strong axis buckling formula is provided. However, the construction space in Taiwan is limited. The space braces are used in buildings is very important. Sliming down the brace and increasing the proportion of using steel in Taiwan can improve designer and user using steel.