基于向量有限元的深水管道屈曲行为分析

BUCKLING ANALYSIS OF DEEPWATER PIPELINES BY VECTOR FORM INTRINSIC FINITE ELEMENT METHOD

局部屈曲破坏是深水管道运行的最大安全问题之一。采用创新性的向量式有限元方法(VFIFE)分析深水管道结构屈曲行为,推导考虑材料非线性的VFIFE空间壳单元计算公式,编制Fortran计算程序和MATLAB后处理程序,开展外压下深水管道压溃压力和屈曲传播压力计算、压溃和屈曲传播过程模拟。开展全尺寸深水管道压溃试验,进行深水管道压溃压力和压溃形貌分析,对比验证了VFIFE、试验、传统有限元方法(FEM)得到的结果。结果表明:VFIFE能够直接求解管道压溃压力和屈曲传播压力,模拟管道屈曲和屈曲传播行为,计算结果符合实际情况,与压溃试验、传统有限元方法符合较好,并具有不需特殊计算处理、全程行为跟踪等优势,可以为深水管道结构屈曲行为分析提供一套新的、通用的分析策略。

Local buckling damage is one of the biggest safety issues during the operation of deepwater pipelines.The innovative vector form intrinsic finite element method(VFIFE)is used to analyze the buckling behavior of deepwater pipelines.After deriving the calculation formula of VFIFE space shell elements considering the nonlinear elastoplastic material,we developed a Fortran calculation program and a MATLAB post-processing program to simulate the collapse and buckling propagation process.The collapse pressure and the buckling propagation pressure were calculated.A full-scale pressure chamber test was conducted to analyze the buckling load and buckling morphology.The VFIFE results were compared with those of the test,traditional finite element method(FEM)and DNV method.The VEIFE can directly simulate the pipeline collapse,the buckling propagation,the collapse pressure,and the buckling propagation pressure.The VFIFE results are in line with the actual situation and in good agreement with those of the other methods.The VFIFE has the advantages of not requiring special calculation processing and tracking of the entire behavior,thus providing a new and universal analytic strategy for buckling simulation of deepwater pipelines.