爆炸荷载下聚脲涂覆含局部缺陷油气管道的失效判定研究

Failure determination of polyurea coated oil and gas pipelines with local defects under blast load

通过埋地静爆试验,对经聚脲弹性体材料加固的含局部缺陷埋地油气管道抗爆性能及损伤评价进行研究,同时结合所得试验数据进行数值模拟,建立了浅埋爆炸荷载下聚脲弹性体材料加固含局部缺陷埋地油气管道损伤失效评估准则。结果表明:在折合距离为0.23 m/kg 1/3试验条件的浅埋爆炸荷载作用下,含局部缺陷普通管道与含局部缺陷聚脲管道迎爆面均发生了明显凹陷变形,含缺陷聚脲管道凹陷变形量较前者降低28.87%,且管道迎爆面及端部连接处易于遭受损伤;含局部缺陷普通管道迎爆面超压高于含局部缺陷聚脲管道且变形响应时间早于后者,表明聚脲材料可以有效降低爆炸冲击波压力峰值和推迟爆炸冲击波的作用时间。在进行爆炸荷载作用下管道的损伤失效判定时引入衡量管道横截面变形的截面临界椭圆度指标,最终建立了基于管道截面临界椭圆度的聚脲涂覆含局部缺陷埋地油气管道的超压-冲量损伤准则及判定公式。

Here,through buried static explosion tests,anti-explosion performance and damage evaluation of buried oil and gas pipelines with local defects reinforced with polyurea elastomer materials were studied.At the same time,numerical simulation was performed based on the obtained test data,and a damage failure evaluation criterion for buried oil and gas pipelines with local defects reinforced with polyurea elastomer materials under shallow buried explosion load was established.The results showed that under shallow buried explosion load and the test condition of a reduced distance of 0.23 m/kg 1/3,both ordinary pipeline with local defects and polyurea covered pipeline with local defects have obvious concave deformation on their blast facing surfaces,the concave deformation of the latter decreases by 28.87%compared to the former,pipeline blast facing surface and end connection are easy to damage;overpressure on blast facing surface of the former is higher than that of the latter,and the former’s deformation response time is earlier than that of the latter,so polyurea materials can effectively reduce peak pressure of blast shock wave and delay the action time of blast shock wave;when determining damage failure of pipeline under blast load,the critical ellipticity index is introduced to measure pipeline cross-section deformation,the pressure-impulse(P-I)damage criterion and determination formula for buried polyurea covered oil and gas pipeline with local defects are finally established based on critical ellipticity of pipeline cross-section.