End-Plate and All-Bolted Moment Connections for Seismic Loading

9416171 Murray在Northridge地震后，许多关于钢抗矩框架梁法兰与柱法兰焊缝断裂的报道表明需要一种新的连接结构。没有端板力矩连接窘迫或故障的报告。在本项目中，将研究端板和全螺栓力矩连接，以开发一种替代现场焊接连接的方法。由于这两种连接类型都需要张力螺栓，并且存在撬撬力相关的问题，因此在梁张紧法兰或三叉张紧腹板的对面放置垫片。使用垫片可确保螺栓张力不会增加，直到端板或三通法兰与柱法兰分离。如果设计是这样的，预紧力足以发展连接梁的强度，实际上连接是在螺栓拧紧时进行测试的。该项目包括三个任务：任务一是进行调查，以确定端板或全螺栓力矩连接是否因北岭地震而出现损坏或破坏。任务二是为端板和全螺栓连接设计程序的发展，这是一个相对简单的程序，因为不需要考虑撬力的影响。任务III是一组四个验证测试，每个连接类型两个。每组中的一个测试将被设计为连接处于控制极限状态，第二个测试将被设计为梁处于控制极限状态。成功完成所提出的研究将导致钢梁与柱的弯矩连接，不需要焊接，但具有足够的强度来抵抗地震事件的大力。这是北岭地震项目。＊＊＊

9416171 Murray Numerous reports of fractures in beam flange-to-column flange welds in steel moment resisting frames after the Northridge earthquake suggest the need for a new connection configuration. No reports of end-plate moment connection distress or failure are known. In this project the endplate and all-bolted moment connections will be studied to develop an alternate to field welded connections. Because both of these connection types require tension bolts and the associated problems with prying forces, a shim plate is placed opposite the beam tension flange or the tee-stub tension web. Using the shim ensures that the bolt tension will not increase until separation of the end-plate or tee stub flange and the column flange occurs. If the design is such that the pretension force is sufficient to develop the strength of the connected beam, in effect the connection is tested at the time the bolts are tightened. The project consists of three tasks: Task I is a survey to determine if end-plate or all-bolted moment connections exhibited distress or failure because of the Northridge earthquake. Task II is the development of a design procedure for shimmed end-plate and all-bolted moment connections, which is a relatively uncomplicated procedure because the effects of prying forces do not need to be considered. Task III is a set of four verification tests, two for each connection type. One test in each set will be designed so the connection is the controlling limit state and the second so the beam is controlling limit state. Successful completion of the proposed research will result in a steel beam-to-column moment connection which does not require welding but with sufficient strength to resist large forces from seismic events. This is a Northridge Earthquake project. ***