Collapse Behaviours of Stiffened Panels Under Longitudinal Compression Considering Heating and Cooling Processes

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.