The fire accidents casually happen during operation of ship, which would influence the load carrying capacity of stiffened panel of ship structures due to the thermal load. The present paper aims to understand the influence of thermal loads on the collapse behaviour of stiffened panels under longitudinal compressive load. Considering the heating and cooling down processes, the collapse behaviours of the stiffened panels under combined in-plane displacement and heat loads representative of fire accident are simulated in the FE (finite element) analysis herein. Firstly, the thermal load is considered to investigate the stress state of the stiffened panels during heating and cooling processes. It is found that the stiffened panels would collapse during thermal loads for the structure with large heated zone. After that, the longitudinal compression loads are applied to assess the collapse strength of the stiffened panels. The parametric studies including different geometrical dimensions and areas of heat zone are performed in detail to quantify the effects of heat loads on the collapse behaviours of stiffened panels. It is found that the expansion could produce biaxial stress state that depends on not only in-plane stiffness but also collapse modes, and for stiffened panels with various heated area the cooling down to room temperature induce similar ultimate strength to that without considering heat loads.

中文翻译：

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考虑加热和冷却过程的纵向压缩加劲板的坍塌行为

火灾事故是在船舶运行过程中偶然发生的，由于热负荷，会影响船舶结构加劲板的承载能力。本文旨在了解在纵向压缩载荷下热载荷对加劲板坍塌行为的影响。考虑到加热和冷却过程，在本文的有限元分析中模拟了加筋板在平面内位移和代表火灾事故的热负荷下的塌陷行为。首先，考虑热负荷以研究在加热和冷却过程中加劲板的应力状态。已经发现，对于具有大加热区的结构，加劲板在热负荷期间会塌陷。之后，施加纵向压缩载荷以评估加劲板的塌陷强度。进行了包括不同几何尺寸和加热区面积在内的参数研究，以量化热负荷对加劲板塌陷行为的影响。结果发现，膨胀可能会产生双轴应力状态，该状态不仅取决于平面内的刚度，还取决于坍塌模式，对于具有各种加热区域的加劲板，冷却至室温所产生的极限强度与不考虑热负荷的情况相同。进行了包括不同几何尺寸和加热区面积在内的参数研究，以量化热负荷对加劲板塌陷行为的影响。结果发现，膨胀可能会产生双轴应力状态，该状态不仅取决于平面内的刚度，还取决于坍塌模式，对于具有各种加热区域的加劲板，冷却至室温所产生的极限强度与不考虑热负荷的情况相同。详细研究了包括不同几何尺寸和加热区面积在内的参数研究，以量化热负荷对加劲板塌陷行为的影响。结果发现，膨胀可能会产生双轴应力状态，该状态不仅取决于平面内的刚度，还取决于坍塌模式，对于具有不同加热面积的加劲板，冷却至室温所产生的极限强度与不考虑热负荷的情况相同。