EAPSI: Mitigating earthquake induced failure and improving economic viability of steel special moment frames

钢特殊弯矩框架（smf）是世界上最常用的减轻地震影响的系统之一。在1994年的北岭地震和1995年的孝古肯-南部地震之后，人们观察到钢框架，特别是梁和柱之间的连接，受到了严重的破坏。先前的研究表明，空心结构截面（HSS）可以提高smf中柱的效率，但由于空心结构截面的几何形状，这种配置可能特别困难。需要一种简单的、经济可行的连接细节，在地震激励下表现良好。该项目的第一阶段将重点加强HSS柱和宽法兰梁之间的梁柱连接。第二阶段将是通过使用专用粘合剂来消除梁接头中的焊接。该项目将与日本北海道大学钢结构梁柱连接、结构力学和地震工程领域的知名专家冈崎泰一郎博士合作。梁柱亚组合试件将使用准静态加载协议进行测试，模拟地震激励对smf的影响。后续试验将进行，以提高连接的性能，减轻塑性流动约束和低周疲劳的影响。然后，结果将被分析并用于开发预合格的力矩连接。此外，宽法兰粘接梁接头将在三点和四点弯曲下进行测试。试验结果将用于推导剪力和弯矩相互作用的设计方程。国家科学基金会EAPSI奖是与日本科学促进会合作资助的。

Steel Special Moment Frames (SMFs) are one of the most commonly used systems to mitigate the effects of earthquakes throughout the world. After the 1994 Northridge and 1995 Hyogoken-Nanbu earthquakes, severe damage to steel moment frames, in particular the connections between the beams and columns, was observed. Previous research stated that hollow structural sections (HSS) increase the efficiency of columns in SMFs, but this configuration can be particularly difficult because of the geometry of hollow structural sections. There is a need for a simplistic, economically viable connection detail that performs adequately under seismic excitation. The first phase of this project will focus on the enhancement of beam-to-column connections between HSS columns and wide-flange beams. The second phase will be an investigation into the elimination of welding in beam-splices by utilization of a specialized adhesive. This project will be a collaborative effort with Dr. Taichiro Okazaki, a renowned expert in the area of steel structure beam-to-column connections, structural mechanics, and earthquake engineering at Hokkaido University in Japan.Beam-to-column sub-assemblage specimens will be tested using a quasi-static loading protocol, simulating the effects of seismic excitation on SMFs. Subsequent tests will be carried out to improve the performance of the connection and mitigate the effects of plastic flow restraint and low-cycle fatigue. Then, the results will be analyzed and used to develop a pre-qualified moment connection. In addition, wide-flange adhesive beam-splices will be tested under both three and four point bending. The results of the tests will be used to derive a design equation for the interaction of shear force and bending moment. The NSF EAPSI award is funded in collaboration with the Japan Society for the Promotion of Science.