火灾后泡沫铝填充钢管柱扭转性能研究

Study of Torsional Property of Square Steel Tube Column Filled with Foam Aluminum after Fire

通过对火灾后空钢管柱和泡沫铝填充钢管柱进行扭转试验,分析泡沫铝孔隙率、含钢率等参数对泡沫金属钢管柱火灾后扭转性能的影响。试验结果表明,高温后泡沫铝填充钢管柱中填充泡沫铝出现收缩塌陷,钢管表面氧化层出现明显的脱落现象;火灾后泡沫填充钢管柱屈服平台阶段很长,且没有明显的强化阶段,承载能力显著下降,约为火灾前的1/2。与空钢管相比,火灾后泡沫铝填充钢管柱的承载能力和变形能力都有显著的提高。

Torsion tests of hollow steel tubes and steel tubes filled with foam aluminum after fire have been carried out. The influencing factors, such as the ratio of steel, porosity of foam aluminum, on the static torsional behavior of the steel tube filled with foam aluminum after fire are also investigated. Based upon the test results, the uniaxial torsional curves of the steel tube filled with foam aluminum after fire are analyzed. It is found that foam aluminum filled in tube was systolic collapse after high temperature. Oxide layer of the steel pipe had an exfoliation phenomenon. The uniaxial torsional curves of the steel tube filled with foam aluminum after fire have the longer plastic collapse region, and have no obvious hardening stage. The ultimate torsional bearing capacity of the steel tubes filled with foam aluminum after fire is half of that of before fire. Compared with hollow steel tubes, the deformation and ultimate torsional strength of steel tubes filled with foam aluminum after fire are improved.