考虑火源位置的船舶机舱火-热-结构耦合研究

为准确分析真实火灾条件下的船舶机舱结构力学行为,克服传统标准温升法的缺陷,提出基于火灾动力学模拟器(FDS)和ANSYS的火-热-结构力学耦合分析方法;采用FDS仿真模拟真实火灾场景,获得近机舱内壁面处时变温度场信息,以此温度场信息为边界条件,传输到结构力学行为仿真软件ANSYS中,对机舱结构加载温度荷载并进行瞬态热分析,再对舱室结构开展热-力耦合计算,通过改变火源位置,研究船舱结构体在不同火源位置下的力学响应特性。结果表明:不同火源位置场景下机舱结构应力分布不均匀,当火源高度为2 m时,产生的最大温度应力为76 MPa;舱室结构防火安全设计应重点关注真实火灾情形下的非均匀受热。

Study on fire-thermal-structural coupling of ship engine rooms considering fire location

In order to accurately analyze mechanical behavior of ship engine room structures under real fire conditions and address insufficiency of traditional standard fire temperature-time curve technique,a coupling analysis method of fire,heat and structural mechanics by combing FDS with ANSYS was proposed.FDS was employed to simulate real fire,and time-varying temperature field information near inner walls of ship engine rooms was obtained,which was used as the inputting variable and transmitted to structural mechanical behavior simulator ANSYS.Then,temperature load of cabin structure was loaded and transient thermal analysis was carried out,thermal mechanical coupling calculation was performed.Finally,by changing fire source position,mechanical response characteristics of cabin structures under different fire source positions were investigated.The results show that stress distribution of the structures is uneven under different fire location scenarios,and the maximum temperature stress is 76 MPa when fire height is 2 m.Fire safety design should focus on cases of non-uniform heating of structures in real fire.