Method and system for evaluating axial deformation bearing capacity of annular welding joint of pipeline

Abstract

The invention discloses a method and system for evaluating the axial deformation bearing capacity of a pipeline ring welding joint. The method comprises the steps: 1, building a finite part model according to the size structure of a pipeline; 2, setting boundary conditions of the finite part model; 3, setting material performance in the finite part model; 4, applying an outward displacement load to the other end face away from the welding seam, the displacement load is gradually increased, the thickness change rate of the pipe wall in the displacement load increasing process is calculated, and axial displacement and thickness change rate data clouds on each pipeline section under each time of displacement loading are obtained under different welding seam size structures and material properties; and 5, taking the thickness reduction rate and the axial average strain of the pipeline as judgment criteria, and integrating the welding seam size structure and the material performance corresponding to the minimum thickness reduction rate and the maximum axial average strain to obtain the optimal axial deformation bearing capacity of the annular welding joint of the pipeline. and calculating and evaluating the pipeline deformability of the ring welding joints with different sizes and performances in each region.

Description

technical field [0001] The invention belongs to the field of petroleum and natural gas pipelines, and relates to a method and a system for evaluating the ability of pipeline girth welding joints to withstand axial deformation. Background technique [0002] Long-distance oil and gas pipelines pass through various terrain and landform areas. Due to stratum dislocation, landslides, earthquakes and geological disasters and temperature changes during laying and operation, the pipeline will bear external forces exceeding the yield strength of the material, and displacement will inevitably occur. The pipeline girth weld is a continuum with uneven structure, structure and mechanical properties. When the pipeline is displaced, it is easy to produce concentrated deformation and fracture, which is the weak link of the structure. How to ensure that the girth welded joint will not be damaged in the case of large displacement of the pipeline requires an accurate evaluation of the deformat...

AI Technical Summary

Problems solved by technology

This method is relatively accurate for calculating and evaluating the stress and fracture capacity of pipelines, but it is difficult to accurately calculate and evaluate the deformation capacity of pipe girth welded joints

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