Y型圆钢管节点耐火性能的有限元分析

Finite Element Analysis on Fire Resistance of Circular Tube Y-joints

利用有限元软件ABAQUS对Y型圆钢管节点在恒载条件下的耐火性能进行了有限元分析。在已有试验研究成果的基础上,建立验证模型并与试验数据相比较,验证了建模方式的准确性和可靠性。根据Eurocode3中对钢材相关属性的描述,建立参数分析模型,分析比较了Y型圆钢管节点的几何参数θ,β,γ和荷载比n对管节点耐火性能的影响,发现随着荷载比的增大,节点的耐火性能大幅降低;相同荷载比条件下,β越大,其耐火性能越好;当荷载比很小的时候,θ越大,其耐火性能越好,但随着荷载比的增加,θ对节点的耐火性能影响变小;γ对于管节点的耐火性能基本没有影响;荷载比n越大,由于钢材膨胀产生的约束反力越小,但却远大于外荷载所引起的反力,严重影响Y型管节点耐火性能。

The fire resistance of circular tube Y-joints was investigated by using finite element software ABAQUS under the rising temperature.Based on existing experimental research results,accuracy and reliability of the modeling method were validated by building verification models and comparing with the experimental data.Analytical models with different parameters were established according to the description of relevant properties of steel in Eurocode 3.The effect of geometrical parameters θ,β,γ and load ratio n on the fire resistance of circular tube Y-joint was investigated.The fire resistance of the joints significantly reduces with increase of the load ratio n.In the condition of the same load ratio,the bigger β results in the better the performance of fire resistance.When the load ratio is small,the bigger θ,the better the performance of fire resistance is obtained and the fire resistance of joint decreases with the increase of the load ratio.γ has little effect on the fire resistance of the joints.An increasing load ration seriously affects the fire resistance ofcircular tube Y-joint,resulting from that the decreasing constraint reaction force generated by expansion of steel,which is greatly bigger than the reaction force caused by the applied load.