Research Of A New Buckling-Restrained Braces (BRB) On Engineering Application

Setting braces in frame structure can improve the lateral stiffness of the framework to a certain extent and reduce the story drift of the structure.However,if the braces are the traditional braces, they will most likely to buckle because of pressure under rare earthquake , So the capacity to resist earthquake of the structure will significantly decrease and the risk to collapse of the structure will increase. In order to improve the buckling performance of the braces and ensure they do not occur to buckle under the earthquake,compared with the traditional center braces f the field of engineering proposes a kind of braces to avoid buckling,called Buckling-Restrained Braces(BRB).This kind of braces have been wildly used in earthquake-prone areas ,for example, the U.S., Japan and China, Taiwan and so on, and they have also showed good seismic performance in the earthquake.After decades of development and application, it has formed a wide variety of components with different materials, forms, and species for BRB.However, most of these braces exist so many problems as insufficiency of cross-section types and node connectivity to apply to the actual projects. For the simple forms, the core components of them often lack the carrying capacity and can not be used in some high-rise buildings. This paper proposes a new section of the buckling restrained brace, it is jointly developed by the Guangdong Provincial Academy of Building Research Earthquake Research Centerand Guangzhou University with a new type of buckling restrained brace——Pinned connection-Dual channel steel -Buckling-Restrained Brace (It has applied for national patent .)First,the paper will explain the concept, development and application of design theory of the BRB in general.The paper describes the structure, form and features of this new BRB and how to determine the mechanical properties, the mechanical models,and related seismic performance indicators of it which will provide design parameters and design information for the follow-up structural design of the new BRB frame.The paper describes the analysis and design methods of this new BRB applied in practical engineering and achieve it with structural design and analysis software——ETABS. In this process, it emphasis on the analysis of the seismic performance of the new BRB .The paper cites an engineering example——Laboratory Centre of Guangdong Provincial Academy of Building Research to Compare and analysis it with adding the new BRB before and after to summarize its seismic performance of the pros and cons and evaluate its applicability.