基于SPH-FEM耦合法的含缺陷输气管道爆炸冲击响应研究

针对大口径埋地输气管道发生物理爆炸对并行含体积缺陷邻管的冲击行为，利用LS-DYNA和LS-PREPOST有限元软件建立基于光滑粒子流体动力学-有限单元法的管-土-炸药耦合模型，分析不同缺陷深度、不同缺陷表面积、不同缺陷位置和不同爆心距下邻管的动力响应；基于爆腔预估公式和峰值振速经验公式，验证了所建耦合模型的可靠性，并通过设计算例开展多工况分析。研究结果表明:迎爆面上的缺陷处为动力响应的热点区域，最大响应特征值（应力、位移与振速）位于缺陷中心处，随缺陷深度的增加或管间距的减小特征值增速由平缓到急剧；相比缺陷位置和表面尺寸对管道的扰动程度，缺陷深度和爆心距对管道的动力响应影响较大；在本研究的条件下，建议埋地并行输气管道的安全间距不应小于5.16 m，且腐蚀深度不大于管道壁厚的0.633 6倍。研究结果可为埋地输气管道极端灾害下的风险评估提供技术支撑，为并行管道可能的抗爆隔爆设计提供模拟数据支持。

Research on explosion impact response of defective gas pipeline based on SPH-FEM coupling method

In view of the impact behavior of the physical explosion of large diameter buried gas pipeline to the parallel adjacent pipeline with the volume defects, the pipeline soil explosive coupling model based on the smoothed particle hydrodynamics and finite element method (SPH-FEM) was established by using the LS-DYNA and LS-PREPOST finite element software, and the dynamic response of the adjacent pipeline under different depths, surface area and positions of defect and different distances to explosion center was analyzed. The reliability of the coupling model was verified based on the prediction formula of explosion cavity and the empirical formula of peak vibration velocity, and the multiple conditions analysis was carried out through the designed example. The results showed that the defect on the front explosion surface was the hotspot region of dynamic response, the maximum response characteristic values (stress, displacement and vibration velocity) were located at the center of defect, and the increase speed of the characteristic values changed from flat to sharp with the increase of defect depth or the decrease of pipelines' spacing. The influence of defect depth and distance to explosion center on the dynamic response of pipeline was larger compared with the disturbance degree of position and surface size of defect on the pipeline. Under the conditions of this research, it was suggested that the safety spacing of buried parallel gas pipelines should not be less than 5.16 m, and the corrosion depth should not be larger than 0.633 6 times of the wall thickness of pipeline. The results can provide technical support for the risk assessment of buried gas pipelines under the extreme disasters, and provide simulation data support for the possible anti explosion and flameproof design of parallel pipelines.