穿孔与热辐射耦合作用下固定拱顶钢储罐的失效机理

为获得大型钢制储罐在碎片冲击和池火热辐射耦合作用下的失效机理，采用Abaqus建立了高速碎片穿孔和热辐射耦合作用下固定拱顶钢储罐失效分析的有限元模型，分析了储罐在高速碎片冲击作用下的动力响应和穿孔储罐在热辐射作用下的热屈曲响应，研究了储罐壁面的应力变化过程。结果表明，在热辐射单一作用下，储罐由罐壁-罐顶连接处开始发生热屈曲，并出现褶皱变形；在高速碎片冲击与热辐射耦合作用下，高速碎片冲击导致储罐产生穿孔，储罐从穿孔两侧开始发生热屈曲，而且，穿孔导致塑性变形区及其附近区域产生应力集中，与未受冲击的储罐相比，穿孔储罐的罐壁处于更高的应力水平，更容易发生失稳。因此，穿孔储罐的抗火性能降低，热屈曲模式也发生改变。

Coupling effects of perforation and heat radiation on failure mechanism of fixed-roof steel tank

To study the failure mechanism of a large fixed-roof Q345 steel tank under coupling effects of the fragment impact and pool-fire heat radiation, finite element models of thermal and dynamic response analysis under coupling effects of the high-velocity fragment perforation and heat radiation of a burning tank was established by Abaqus. The dynamic behaviors of a fixed-roof tank subjected to high-velocity fragment perforation were investigated. And the effect of the heat radiation on the thermal buckling behaviors of a perforated tank was analyzed. Moreover, the stress distribution and variation on the cylindrical shell was studied. The results indicated that the thermal buckling of the tank begun from the connection of the cylindrical shell and dome under the single effect of the heat radiation. And the cylindrical shell wrinkled along the circumferential direction with the temperature increasing at the post-buckling state. The reason was that circumferential and meridional stresses alternated between tension and compression to maintain the balance. The tank was perforated, and the thermal buckling of the perforated tank started from both sides of the perforation under coupling effects of the perforation and heat radiation. Moreover, perforation led to stress concentration in the plastic deformation zone and its vicinity. Compared with the unimpacted storage tank, the wall of the perforated storage tank was at a higher stress level and was more prone to instability. Therefore, the fire resistance of the perforated storage tank reduced, and the thermal buckling mode also changed.