火灾下防火涂料破损后约束柱的稳定承载力

Stability Capacity of Restrained Steel Columns after Damage of Fire Retardant Coating in Fire

为考察地震破坏防火涂料后钢柱的抗火性能,根据势能驻值原理推导了约束钢柱两端防火涂料破损后稳定承载力计算方法。分别讨论了防火涂料的破损长度、钢柱的升温以及端部转动约束刚度对稳定承载力的影响。结果表明:破损长度对约束柱稳定承载力影响较大;温度较低时,温度对稳定承载力影响不大,而端部约束刚度对稳定承载力影响较大,温度超过500℃以后,温度对稳定承载力有较大影响,而转动约束刚度对稳定承载力影响变小。

In order to investigate the fire resistance of steel columns after damage of fire protection by earthquake, a method to predict the capacity for stability of restrained steel columns was proposed according to the principle of stationary potential energy. The influences of the length of fire retardant coating damage, column temperature and rotational restrained stiffness on capacity for stability of restrained steel columns were discussed. The results show that the damage length has a significant inflaence on the capacity for stability of rational restrained columns. Further more, when the temperature is low, the temperature has a small impact on the capacity for stability, but the rational restrained stiffness has great effect on the capacity for stability, when the temperature exceeds 500℃, the temperature will hav great impact on the capacity for stability and the rotational restrained stiffness will have little effect on the capacity for stability.