火灾下铝合金方管柱的升温

Temperature rises of square aluminium alloy tubular columns in fire

采用有限元法计算了无保护层和带防火保护层铝合金方管柱在火灾下的温度场,并将计算结果与Eurocode 9升温公式以及实验结果进行比较,考察了截面形状系数、保护层厚度与导热系数比的影响规律。研究结果表明,对于无防火保护的构件,辐射安全系数为1时Eurocode 9预测结果太高,而安全系数0.15的计算结果与实测值和有限元值吻合良好,对于防火保护的构件,Eurocode 9的计算结果和有限元结果非常接近。随着截面形状系数的增加或保护层厚度与导热系数比的减小,相同时间下铝合金方管柱的平均温度越高。

Temperature fields of unprotected and protected square aluminium alloy tubular columns in fire were calculated by finite element method.The calculated temperature results were compared with the results according to the temperature rising formulae in Eurocode 9 and experiment results.The influences of section shape factor and ratio of fire board thickness to thermal conductivity were investigated.The research results showed that,the predicted results of Eurocode 9 are too high when the safety coefficient due to radiation is taken as 1 for unprotected members.When the coefficient is taken as 0.15,the predicted results agree well with the test results and finite element results.As for protected members,the comparison of predicted results of Eurocode 9 and finite element method is quite good.With the increase of section shape factor or reduce of the ratio of fire board thickness to thermal conductivity,the average temperatures of square aluminium alloy tubular columns increase at the same fire duration time.