火灾非均匀温度场下导管架平台T形管节点极限承载力

Ultimate Strength of Tubular T-Joint of Offshore Jacket Structurein Non-Uniform Elevated Temperature Field Caused by Fire

基于热-结构顺序耦合方法,研究T形管节点在不同局部火灾场景下形成的非均匀温度场,并研究高温对极限承载力和失效模态的影响。结果表明:局部火灾在主管中形成的非均匀温度场沿主管轴向和环向上均产生显著的温差。局部火灾对管节点的极限承载力结果表明:若局部火灾中心位置距管节点中心越近,则其对管节点极限承载力的影响越大;当局部火灾中心温度超过600℃时,管节点的极限承载力随温度的升高而明显下降;在不同火灾工况下,管节点均发生主支管相贯区域塑性破坏。

Based on the thermal-structural sequential coupling method,the non-uniform temperature field in the tubular T-joint caused by different local fire conditions are investigated,and the effects of elevated temperature on the ultimate strength and failure model of the tubular T-joint are studied.The results indicate that a non-uniform temperature field is formed,because a large temperature difference along the axial and annular directions of the chord occurs in the temperature field caused by local fire.The results of the ultimate strength of the tubular joints under local fire show that:the closer the local fire is to the center of the T-joint,the greater its influence on the ultimate strength of the T-joint;when the central temperature of the local fire exceeds 600℃,the ultimate strength of the T-joint decreases significantly with the increase of temperature;the failure model of the tubular T-joint is the plastic failure of intersection of chord and brace at different fire cases.