梁腹板开孔式钢结构梁柱节点性能研究.docVIP

 梁腹板开孔式钢结构梁柱节点性能研究 刘剑峰，陈世鸣** （同济大学土木工程学院，上海 200092） 5 10 15 20 25 30 35 40 摘要：根据框架“强柱弱梁，节点更强”的抗震设计原则，在节点域附近梁腹板开圆孔是为 了解决地震荷载作用下钢框架梁柱节点焊缝处可能发生脆性破坏而提出的一种新型节点。该 种节点在具备良好建筑功能的同时，不会大幅降低梁的整体和局部稳定性。本文对梁腹板开 孔节点与传统梁柱节点进行了静力单向加载和低周反复加载的有限元分析模拟。计算分析结 果表明：采用梁腹板适当开孔节点形式，能在节点承载力和刚度下降不大的前提下，迫使塑 性铰出现在梁截面削弱位置，使塑性发展区域远离梁根部焊缝区，达到降低节点发生脆性破 坏的可能性，最终提高结构抗震性能的目的。 关键词：结构工程；钢框架结构；腹板开孔；有限元分析；滞回曲线 中图分类号：TU392.1 STUDY ON PERFORMANCE OF THE BEAM TO COLUMN JOINTS WITH OPENING IN BEAM WEB LIU Jianfeng, CHEN Shiming (School of Civil Engineering,Tongji University, ShangHai 200092) Abstract: According to the seismic design principles of frames like strong column and weak beam, strong joint and weak member, the opening in beam web (OBW) joint is a new type of beam to column connection of steel moment resisting frame, which is addressing to avoid brittle failure that would likely take place in the weld foot of beam to column joint under the seismic load. Though the holes in the web would weaken the cross section properties of the beam, the overall and local stabilty of this type of joint will not deteriorate dramatically, and the joint is capable well of rotation capacity. In this paper, a comparative finite element study is conducted to simulate joints with web openings and the conventinal steel beam to column joints under the statically monotonical loading and under the low-cyclic reversed loading. Compared with conventional joints, the potential plastic hinge occurs at the weakening section which is away from the welding foot of the beam to column connection in the joint with web opening, so that the likely brittle failure is avoided and better seismic performance is achieved. Keywords: structural engineer; steel frame; web opening; FEM; hysteretic curve 0 引言 刚性钢框架，又称为抵抗弯矩框架，它在框架平面内不设支撑，依靠梁柱节点自身承受 弯矩的能力抵抗水平荷载。梁柱连接的性能对刚性钢框架整体受力性能有举足轻重的影响。 长期以来，刚性钢框架由于被认为具有优越的抗震性能而被广泛应用于抗震设防地区。但在 1994 年美国 Northridge 地震和 1995 年日本 Kobe 地震中，许多刚性节点钢框架建筑因节点 的塑性变形能力不足而在节点处产生脆性裂缝。震害调查显示：罕遇地震作用下，刚性节点 钢框架结构在构件屈服前，其梁柱节点连接焊