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为了确定事故型撞击荷载作用下大型LNG储罐穹顶的局部破坏形态,以ф101.6 mm NPS法兰冲击能量为参照,选取穹顶局部壳体为靶体,利用等效飞射物弹体自由落体撞击靶体进行了15个工况冲击试验。通过对试验结果分析研究,标定了冲击成坑、冲击震裂、冲击剥落屈曲、冲击侵彻屈曲、冲击贯穿屈曲5种破坏形态,并给出了特征形态图。通过引入薄钢板弹道极限速度对侵彻贯穿屈曲破坏形态的侵彻深度进行修正,给出了以侵彻深度与穹顶厚度比值。这一无量纲参数为基准的破坏形态判断标准。最后,提出了事故型撞击荷载作用下LNG储罐穹顶的破坏等级划分标准,验证了Petry公式和BRL公式用于侵彻深度估算的有效性。
In order to determine the local failure mode of the dome of a large LNG tank under accidental impact load, with reference to the impact energy of flange of Ф101.6 mm NPS, partial shell of dome is selected as the target and free-fall Impact on the target body carried out 15 test conditions. Through the analysis of test results, five kinds of failure modes of impact crater, impact crack, impact peel buckling, impact penetration buckling and impact penetrating through the buckling are calibrated and the characteristic morphological maps are given. By introducing the limit velocity of the thin steel ballistic trajectory to penetrate through the buckling damage penetration depth is modified to give the penetration depth and the ratio of the thickness of the dome. This dimensionless number is the criterion for determining the damage pattern. Finally, the criteria for classifying the damage grade of LNG storage domes under accidental impact loads are proposed, and the validity of Petry formula and BRL formula for penetration depth estimation is verified.