加筋板是典型船体承载构件,考虑火灾高温作用下材料性能的变化,根据热弹塑性有限元理论,基于名义升温曲线,研究防火涂层对加筋板结构高温响应特性和剩余强度的防护作用以及涂敷位置对加筋板失效模式的影响,为结构性能评估和结构防火设计提供参考.数值分析表明:防火涂层能有效减缓结构升温诱发的应力升高和挠度增加;整体涂敷不改变结构整体屈曲伴随加强筋侧倾的失效模式,而显著推迟了失效时间,对保持结构高温剩余强度有明显效果;局部涂敷会改变结构的失效特性,仅带板涂敷下发生整体失效,仅加强筋涂敷下发生梁柱型失效伴随腹板的局部屈曲;整体涂敷对加筋板剩余强度的防护效果最佳,仅带板涂敷次之,而仅加强筋涂敷的防护能力较弱,局部涂敷的防护性能主要取决于结构的受热和失效模式.

Stiffened panel is a typical strength member in ships. Considering the change of material properties under the action of fire and high temperature, according to the thermal elastic-plastic finite element theory, based on the nominal temperature-time curve, the protective effect of the passive fire protection layer on the high temperature response characteristics and the residual strength of the stiffened panel and the influence of coating positions on the failure mode of the stiffened panel are studied, which provides reference for structural performance evaluation and structural fire protection design. Numerical analyses indicate that passive fire protection layer can effectively slow down the increase of stress and deformation induced by temperature rise. Overall coating does not change the failure mode of the overall buckling of the structure accompanied by the tripping of the stiffener, but significantly delays the failure time and has an obvious effect on maintaining residual ultimate strength. Partial coating will change the failure characteristics of the structure. Overall failure occurs when only the plate is coated, and beam-column failure occurs when only the stiffener is coated, accompanied by local buckling of the web. Overall coating shows the best protective performance on the residual strength of the stiffened panel, followed by plate coating. Stiffener coating, however, has a weak protective effect. The protection performance mainly depends on the heating and failure mode of the structure.