天然气管道的屈曲变形模拟

在外荷载作用下，埋地管道的屈曲失效受诸多因素影响，外压、内压、轴向力和弯矩均会使管道产生屈曲，屈曲变形较为复杂。以西660X7．1钢管发生局部非均匀屈曲为例，通过有限元方法开展管道的屈曲失稳研究，分析不同载荷下管体的变形形式，进而判断造成钢管屈曲变形的主要原因：钢管变形处受到较大弯矩作用，而弯矩是斜坡钢管与土壤之间摩擦力不足，管道输气压力循环波动，土壤随气温季节性冻结、融化产生的管道周期性轴向载荷所致。（图9，参6）

Simulation on buckling deformation of natural gas pipeline

Under external loads, buckling failure of buried pipeline is subject to a number of factors such as external pressure, internal pressure, axial force and bending moment, all of which can cause buckling of pipeline. Therefore, the buckling deformation is complex. ~660~7.1 steel pipe subject to partial non-uniform buckling are taken as an example. The finite element method is used to carry out research on the buckling instability of the pipeline to analyze pipe body deformation forms under different loads and further determine the main cause for steel pipe buckling deformation. The steel pipe is subject to a large bending moment at the deformation point and the bending moment results from periodic axial pipeline load due to lack of friction between slope steel pipe and soils, circulating fluctuation of pipeline gas pressure and seasonal soil freezing and melting with temperature change. （9 Figures, 6 References）