Local fracture‐induced phenomena in steel moment frames
Local fracture‐induced phenomena in steel moment frames
复制标题
钢弯矩框架中的局部断裂引起的现象
DOI：
10.1002/eqe.839
复制
发表时间：
2009
影响因子：
4.5
通讯作者：
S. Mahin
中科院分区：
文献类型：
--
作者：
J. Rodgers;S. Mahin
1994年北岭6.7级地震后，许多钢框架结构建筑的梁柱焊接节点出现脆性断裂。这种断裂会导致连接强度和刚度的迅速丧失，以及在断裂时连接存储的应变能的突然释放。断裂后，在与连接相邻的构件中以及整个结构中立即出现许多高度瞬变现象。在一个1/3比例的两层单跨钢框架的振动台试验中，观察到了四种重要的局部现象：(A)梁的变形形状的变化；(B)相邻构件中弯矩分布的变化；(C)弹性波的产生和传播；以及(D)构件水平上的动力模态响应。由于这些现象的高度瞬变性质，它们被观察到对系统的整体行为具有二阶效应。相比之下，断裂导致的局部强度和刚度的降低对系统行为的影响要大得多。版权所有©2008 John Wiley&Sons，Ltd.
Brittle fractures were observed at the welded beam‐to‐column connections of a number of steel moment frame buildings following the M6.7 1994 Northridge earthquake. Such fractures cause a rapid loss of connection strength and stiffness, as well as a sudden release of the strain energy stored by the connection at the time of fracture. Immediately following the fracture, a number of highly transient phenomena occur locally in the members adjacent to the connection, as well as globally in the structure as a whole. Four significant local phenomena were observed locally during shaking table tests of a one‐third scale, two‐story, one‐bay steel moment frame in which quasi‐brittle beam‐to‐column fractures occurred: (a) change in beam deflected shape; (b) change in moment distribution in adjacent members; (c) generation and propagation of elastic waves; and (d) initiation of dynamic modal response at the member level. Owing to the highly transient nature of these phenomena, they were observed to have second‐order effects on overall behavior of the system. In comparison, the reductions in local strength and stiffness caused by the fractures had much more significant effects on system behavior. Copyright © 2008 John Wiley & Sons, Ltd.