高强度钢框架梁柱节点低周疲劳断裂性能试验研究

高强度钢结构节点的低周疲劳断裂性能是影响其抗震性能的关键因素，对于高强度钢结构的抗震设计及其在抗震区的推广应用至关重要。为研究受强震作用高强度钢结构节点的低周疲劳断裂性能，完成了4个高强钢框架栓-焊混接梁柱节点足尺试件的低周疲劳往复加载试验，包括2种不同的焊接孔形式和4种焊接工艺，测得各试件的断裂失效模态及承载性能。基于试验结果，分析了焊接工艺细节及焊接孔形式、钢材强度对高强钢框架梁柱节点断裂性能的影响，研究了这类节点的断裂失效机制。结果表明：当采用有效的构造改进措施，且翼缘焊缝质量得以保证时，高强度钢框架梁柱节点破坏前能承受较大的塑性变形，断裂性能良好。

Experimental study on low-cycle fatigue fracture behavior of high strength steel beam-to-column connection

Low-cycle fatigue fracture behavior of high strength steel (HSS) connection is crucial to its seismic performance. It is important for the seismic design of high strength steel structure and its application in seismic region. To investigate the low-cycle fatigue fracture behavior of HSS connections under rare earthquake, four beam-to-column connections of HSS moment resisting frame were tested under cyclic loads to simulate the earthquake induced loads. Two various welding access holes and four welding technologies were included. Specimens fracture failure modes and bearing capacities were tested. Based on the test results, the influences of the welding technology details and welding access holes shape on the low-cycle fatigue fracture behavior were analyzed; the fracture mechanism of these connections were discussed; the effects of steel strength on connections fracture behavior were analyzed. The results indicate that the high strength steel beam-to-column connection can endure large plastic deformation before failure, if the improved construction details are employed and the flange weld quality is guaranteed. The fracture behavior related indices were obtained as well.