Alternative Details for Steel Beam-To-Column Connections

9501449 Schneider这是给年轻工程研究者的职业奖。本项目的目的是为全焊接和部分约束的抗弯矩连接开发实用和经济的替代细节。显然，从Northridge地震期间观察到的钢连接性能来看，为底部法兰提供延展性是至关重要的。因此，本研究提出了几种可行的连接方案，进行分析和实验研究。为期一年的北岭研究计划的结果将用于确定适当的原型框架和适当的结构钢尺寸进行测试。研究的主要焦点是钢梁柱连接的替代细节的实验性能。一系列大到全尺寸的近实时循环变形试验将在三字梁-柱试件上进行，使用110 kip液压致动器来变形悬臂梁的尖端。变形的施加频率与结构框架在地震振动中梁柱节点可能经历的频率大致相同。此外，还将进行一系列地震模拟试验，以研究节点的真实动力性能。本文的研究成果将对地震工程礼仪产生重要影响。近实时的全尺寸试验将开始解决北岭地震后观察到的关节损伤与实验室观察到的典型关节性能之间的一些差异。为了提高连接的延展性，并减轻与连接高度受限区域相关的一些高应力集中，将测试各种连接方案。＊＊＊

9501449 Schneider This is a career award for young engineering investigators.The object of this project is to develop practical and economical alternative details for the fully welded and the partially- constrained moment-resisting connection. Clearly, from the observed performance of steel connections during the Northridge earthquake, it is essential to provide ductility for the bottom flange. Therefore, this research proposes several viable connection alternatives to be investigated analytically and experimentally. Results from the one-year Northridge research program will be used to determine appropriate prototype frames and appropriate structural steel sizes for testing. The primary focus of the research is the experimental performance of alternate details for steel beam-to column connections. A series of large-to full-scale near-real-time cyclic deformation tests will be performed on tee-shaped beam-column specimens using a 110 kip hydraulic actuator to deform the tip of the cantilevered beam. Deformations will be imposed at approximately the same frequency as a beam-to column joint might experience during the seismic vibration of a structural frame. Also a series of earthquake simulator tests will be conducted to investigate true dynamic behavior of the joints. Results from this research will have a great impact within the earthquake engineering comity. The near-real time full-scale tests will begin to resolve some of the differences between joint damage noted after the Northridge earthquake and typical joint performance observed in the laboratory. Connection alternatives will be tested in an effort to improve the ductility of the connection, and relieve some of the high stress concentrations associated with the highly confined region of the joint. ***