Numerical Analysis Of Seismic Response Of Buried Oil Pipelines In Severe Cold Regions Based On Fluid-Structure Coupling

With economic development and social progress,the pipeline has developed rapidly as a safe and efficient transportation system.Buried oil pipelines are affected not only by the interaction between the pipeline and the fluid,but also by the interaction between the pipeline and the soil and the temperature change of the surrounding frozen soil in the frozen soil layer in the northeast and other cold regions,so consider the frozen soil-pipeline-The interaction of liquid and oil,and the research on fluid-solid coupling and seismic response of buried oil pipelines are of great significance to social development and engineering construction.Based on the three-dimensional solid model of soil-pipe-liquid interaction established in this paper,the thermal-fluid-structure coupling analysis and seismic response analysis of buried oil pipelines considering thermal-fluid-structure coupling under earthquakes are performed.The main work is as follows:1.Use the Soild Works software to establish the model,use ANSYS Workbench finite element analysis software to analyze the heat-fluid-solid coupling of the buried oil pipeline,and study the influence of the temperature field on the buried oil pipeline in severe cold areas.influences.And by changing the four parameters of the pipe diameter,wall thickness,embedding depth and liquid pressure to study the influence of the pipe on the fluid-solid coupling.The results show that when the pipeline is affected by the thermo-fluid-solid coupling effect,the axial stress decreases with the increase of the wall thickness,and increases with the increase of the pipe diameter and liquid pressure.The buried depth of the pipeline has little effect on the axial stress.2.The modal analysis of the buried fluid pipeline with thermo-fluid-solid coupling and the co MParative analysis with the modal of the empty pipe show that the natural frequency of each phase of the pipeline is significantly reduced when the thermo-fluid-solid coupling is considered.The natural frequency is reduced by an average of 9.74%.In comparison,it does not have much effect on the formation of each frequency of the pipeline.Secondly,static analysis of the buried oil pipeline model considering thermal fluid-solid coupling is conducted,and then the motion time history analysis method is used to input EL-centro seismic waves from the three directions of X,Y,and Z for simulation research.The results show that: under the action of earthquake When the seismic wave is input in the X direction,it will have the greatest impact on the destruction of the heat-solid-coupled buried oil pipeline.3.The finite element model of pipeline analysis under the action of temperature field incold region was established to analyze the influence of temperature field on buried oil pipeline under the action of earthquake.As the temperature decreases,the maximum displacement and maximum stress of the pipeline gradually increase under earthquake action,so it is very important to consider the temperature field for the seismic design of the buried pipeline.And study the influence of three parameters of pipeline diameter,wall thickness and embedding depth on seismic performance of pipeline.The calculation result is: the axial stress of the pipeline decreases with the increase of the pipe diameter and wall thickness,and increases with the increase of the embedding depth.