火灾下钢节点牢固性的研究与展望

DISCUSSIONS ON THE ROBUSTNESS OF STEEL CONNECTIONS IN FIRE

阐述了钢结构中节点在常温下和在高温下的行为和设计方面存在的差异,指出采用在常温下的设计方法应用于火灾设计时不合理的地方,并提出在高温下的设计中应该综合考虑节点的牢固性。接着,该文介绍了一组旨在研究常用的节点在高温下的牢固性的试验,并对试验的主要观察现象和结论做了报告。最后,针对性能化设计体系,总结了节点设计中的3个要素,即节点的抗弯能力、抗轴拉/压能力和塑性转动能力之间的关系,并提出了在高温下对节点进行性能化分析和设计的方法。

The behaviour differences between connections and elevated temperatures and the corresponding design requirements of a steel structure are illustrated.It is pointed out that direct application of the design concept for the ambient temperature to a fire safety design is unreasonable because in a fire situation,robustness should be the main concern for connections.The observations and conclusions drawn from a set of tests designed for this purpose are then reported.The relationships among three major parameters in a connection design,i.e.,the moment capacity,the axial force capacity and the rotational capacity of the connection are discussed and a solution for a performance-based connection design is proposed.