含连续不均匀椭圆缺陷管道的屈曲失稳分析OACSTPCD

To investigate the impact of axial continuous nonuniform residual defects on the buckling load-carrying capacity of the submarine pipelines subjected to external pressure,this paper employs numerical simulation methods to study the buckling instability behavior of the axial pipelines with uniform,single-and double-peak oval defects,adopts the RIKS method to calculate the buckling pressures of the pipelines.These results are compared with the results calculated using the DNV-OS-F101 norms.The research verifies the conservatism of DNV norms in predic-ting the buckling pressure of an axial pipeline with nonuniform oval defects and primarily analyzes the excitation po-sitions and the influence parameters of the buckling instability of axial pipelines with continuous nonuniform oval defects.The results show that the buckling pressure of the axial pipeline with continuous nonuniform oval defects is mainly determined via the uniform ovality and the maximum local ovality,and the variation laws of the buckling pressures are different within different ranges of defect spacing.In addition,the range of the rise and fall is affected by the coupling effect between the spacing of oval defects and the maximum ovality.