蒸汽跨越管线含体积型缺陷的塑性极限载荷分析

长输管线在使用与制造过程中会出现各种缺陷,主要以腐蚀造成的体积型缺陷为主。用有限元方法对含体积型缺陷的跨越蒸汽管道进行了极限载荷分析,分析时考虑了大变形弹塑性情况,载荷考虑内压、温度、自重（产生面内弯矩及剪力）及风载荷（产生垂直面弯矩及扭矩）单独及联合作用情况,缺陷位置在近固定墩处,缺陷形状为球形及长条形。分析了缺陷的形状、大小、深度及载荷情况对极限载荷的影响,并分析了管道在上述情况下的失效形式。

Limited Load Analysis of Steam Span Pipeline with Bulk Flaw

Defects commonly occur in manufacture and under service of buried pipeline.The main defects are volume-scale defects caused by corrosion.The collapse loads of aerial crossing steam pipeline with volume-scale defects are analyzed by finite element method.The nonlinear displacement and elastic-plastic material are considered.The loads of internal pressure,temperature,deadweight(caused in-plane bending moment and shearing force) and wind(caused out of plane bending moment and torsion moment) are considered separately and in combination.The defects are near the anchor block.The shapes of defects are spherical or long spherical.How the shape and size of defects or loads condition effect on the limited loads is discussed in the paper.At the same time the failure models of the circular arch pipeline in the above conditions are analyzed.