Development of Link-to-Column Connections for Steel Eccentrically Braced Frames

0000031 Engelhardt本研究项目的目的是开发和验证安全和经济的连接柱连接用于钢偏心支撑框架。1994年北岭和1995年科比地震暴露了根本的缺陷，在美国的设计，详细说明和焊接的做法，在钢框架连接。 然而，最近在这两个国家进行的研究，导致了重大的进步，在理解与钢弯矩连接相关的问题。偏心支撑框架（EBF）提供了一个替代的弯矩框架作为抗侧力系统在钢建筑。 由EBF提供的更高刚度可以提供比弯矩框架更重要的优势，并且自从北岭地震以来已经建造了EBF的使用，许多使用EBF连接到柱的配置。 在这种体系中，杆柱连接对框架的抗震性能和安全性起着至关重要的作用。在北岭地震中，许多导致弯矩框架连接性能差的焊接和设计条件也存在于EBF杆柱连接中。 与此同时，在连接柱连接处的力和非弹性变形需求比在弯矩框架连接处的大得多。 然而，实际上没有研究工作已针对链接到列连接EBF的日期。 尽管如此，在西海岸的主要建筑项目中，EBF的建设仍在进行，这些项目使用了未经测试验证的可疑连接细节。将对抗震钢EBF的连接柱连接进行分析和大规模实验研究。 各种有前途的连接细节将进行调查和完善，使用非弹性有限元研究。 连接性能将通过全尺寸循环荷载试验进行评估，然后制定设计建议。该项目将与日本京都大学的研究人员密切合作进行。 计划中的合作包括美国和日本之间的协调实验研究，京都大学的一名博士生参与美国方面的研究，在京都大学使用美国没有的加载设备对在美国制造的样品进行动态测试。 本计画也将包括与台湾国家地震工程研究中心的额外合作。本计画是在NSF 98-36下的第三年竞赛中获得支持。“美日城市地震减灾合作研究。"

0000031EngelhardtThe objective of this research project is to develop and validate safe and economical link-to-column connections for use in steel eccentrically braced frames.The 1994 Northridge and 1995 Kobe earthquake exposed fundamental deficiencies in US design, detailing and welding practices for connections in steel moment frames. Recent research conducted in both countries, however, has lead to major strides in understanding the problems associated with steel moment connections.Eccentrically braced frames (EBFs) provide an alternative to moment frame as a lateral force resisting system in steel buildings. The higher stiffness provided by an EBF could offer important advantages over a moment frame, and the use of EBFs have been constructed since the Northridge Earthquake, many using a configuration where the EBF link is attached to the column. The link-to-column connection in such systems plays a critical role in the seismic performance and safety of the frame.Many of the welding and design conditions responsible for the poor performance of moment frame connections in the Northridge Earthquake are also present in EBF link-to-column connections. At the same time, the force and inelastic deformation demands at link-to-column connections are substantially greater than at moment frame connections. However, virtually no research effort has been directed towards link-to-column connections in EBF to date. Nonetheless, EBF construction is proceeding on he West Coast for major building projects using questionable connection details that have not been verified by testing.A program of combined analytical and large-scale experimental studies will be conducted on link-to-column connections for seismic-resistant steel EBFs. A variety of promising connection details will be investigated and refined using inelastic finite element studies. Connection performance will then be evaluated using full-scale cyclic loading tests, followed by the development of design recommendations.This project will be conducted in close collaboration with investigators at Kyoto University in Japan. The planned collaboration includes coordinated experimental investigations between the US and Japanese sides, participation of a doctoral student from Kyoto University in the US side research, an dynamic testing of specimens fabricated in the US at Kyoto University using loading equipment not available in the US. This project will also include additional collaboration with the National Center for Research in Earthquake Engineering in Taiwan.This project is supported under the 3rd-year competition under NSF 98-36. "US Japan Cooperative Research in Urban Earthquake Disaster Mitigation."