This invention provides a method for simulating buckling of
subsea pipelines based on the pipeline element method, addressing the problems of low computational efficiency, complex modeling, and low accuracy in existing methods. Based on Euler-Bernoulli beam theory, this invention models the pipeline as a series of efficient pipeline elements.
Internal pressure is converted into
equivalent temperature rise, and the effective
thermal expansion force generated by the
effective temperature rise is applied to both ends of the pipeline element to construct the total
potential energy equation. The second derivative of the total
potential energy equation is performed to obtain the tangent
stiffness matrix of the pipeline element. An updated Lagrange method is used for coordinate transformation. The secant relationship is used to calculate the pipeline element and
soil resistance. A Newton-Raphson incremental-iterative numerical program is established to perform nonlinear analysis of the pipeline, progressively solving for the deformation and stress of the pipeline under complex loads. This invention significantly reduces the number of elements, improves computational efficiency, and accurately simulates nonlinear
pipe-soil interactions. It is applicable to various pipelines, including short pipes, long pipes, and corroded pipes, as well as complex working conditions such as high temperature and
high pressure.