摘要
结合BZ28-1南井口平台导管架,建立了海洋平台结构有限元计算模型。采用弹塑性分析方法,并应用温度升高时钢材的非线性应力/应变关系,采用火灾的标准温度-时间曲线建立平台结构温度随时间的变化模型,基于能量守恒原理建立热传导微分方程,计算热传导和对流对结构温度的影响,分析得到受火区域构件的温度场。依据钢材性能随温度升高的变化,分析火灾荷载下平台结构的响应。火灾发生时,平台结构中的构件在火温的作用下,温度逐渐升高,虽然作用在结构上的荷载不变,但由于钢材的弹性模量和屈服强度都急剧下降,使平台结构的承载能力下降;当温度上升到600℃以上时,平台结构就形成足够数目的塑性铰,使结构达到极限破坏状态。通过计算分析表明,当火灾作用6 min后,着火房间构件发生严重屈曲,但平台结构整体性能保持良好;当火灾作用22 min后,受火区域构件都发生了较大的变形,引起平台结构的毁损和倾覆。
The elastic-plastic analysis method is adopted to analyze the finite element calculation model of BZ28- 1 south platform structure, and the nonlinear stress-strain relation of steel along temperature is applied to the structural analysis. The standard temperature-time curve is adopted to establish the temperature calculation model of fire. Based on energy conservation theory, the heat of conduction, radiation and convection on the platform structure is analyzed, and the temperature field of members subjected to fire is calculated. The temperature of members is rising beeause of fire; although the load on structure isn＇ t changed, the bearing capacity of structure descends obviously because of the sudden drop of Young＇s modulus and yield strength; when the temperature of member rises above 600%, lots of plastic ream is formed on the structure and the structure reaches breaking strength. The members in the fire room buckle severely after 6 minutes, but the integrality performance of the structure is good; after 22 minutes, all members of the fire field buckle severely, which causes the damage and collapse of the platform structure.
出处
《海洋工程》
CSCD
北大核心
2006年第2期21-28,共8页
The Ocean Engineering
基金
国家自然科学基金重点资助项目(50039010)
关键词
海洋平台
火灾荷载
火灾温度场
抗火极限状态
结构响应分析
offshore structure
fire load
fire temperature field
resistance limit state
structural response analysis
