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采用数字模型分析了钢混组合框架在火灾中的结构性能。两种情况下结构的性能是显著不同的。对只带防火保护的外梁与没有任何梁受保护两种情况的结构进行了比较,当边梁被保护时,底板趋向两个方向延伸,因为边梁对板周界应力的发展提供了足够的支撑;当边梁没有被保护时,板只朝一个方向延伸,其受力方式类似于悬链线。与拉伸膜相比悬链线梁为较弱的荷载载运机制。这种弱机制的结果是当边梁无保护时,柱位移向内预示出临近坍塌的可能性。混凝土楼板的应变模式取决于其承载机理,因此与边梁是否保护有关。当边梁有保护时尽管平均拉应变较高,但是最高拉应变都发生在边梁无保护时。反之,当边梁有保护时,在很低的温度,原梁就失稳。研究结论是边梁的结构布局在结构防火等方面具有一定的效果,有些有利,有些有害,然而,一般情况下,有保护边梁可以提供较高的防火等级。
The structural behavior of steel-concrete composite frame in fire was analyzed by numerical model. The performance of the structure is significantly different in both cases. The comparison of the outer beam with fire protection only and the one without any beam protection shows that when the side beam is protected, the bottom plate tends to extend in both directions because the side beam provides enough for the development of plate perimeter stress Of the support; when the side beams are not protected, the plate extends in only one direction, its force is similar to the catenary. Catenary beams are weaker load carrying mechanisms compared to stretched films. The result of this weak mechanism is that when the side beam is unprotected, the column displacement inwardly foreground the possibility of near collapse. The strain pattern of concrete slabs depends on their load-bearing mechanism and therefore on the protection of the side beams. Although the average tensile strain is higher when the side beams are protected, the highest tensile strain occurs when the side beams are unprotected. On the contrary, when the side beam is protected, the original beam is unstable at a very low temperature. The conclusion of the study is that the structural layout of the side beams has some effects on structural fire protection, and some are beneficial and some are harmful. However, in general, the protective side beams can provide higher fire protection levels.