| The anti-corrosion coating of the pipeline would be destroyed or invalid during service,as a result,it will cause corrosion defects due to the effect of external media on the outer wall of the pipeline.Domestic and foreign scholars have conducted studies on the repair technology for corroded pipelines.Composite repair pipeline technology is widely used due to its advantages such as low cost,simple installation,and time saving.However,environmental factors such as temperature and material degradation can influence the composite repair pipeline.In order to explore the influence regularity,this paper considers temperature and material degradation and analyze the ultimate load capacity of the repaired pipeline.Complete the calculation of the ultimate internal pressure of the corroded pipeline and the thermal stress of the undamaged pipeline by finite element method,and compare them with the calculation of the residual strength theory and the thermal stress theory.Then the accuracy of the finite model can be verified.The thermal stress distribution of pipelines is obtained by the thermal mechanical coupling method.At the same time,the stress state and ultimate load capacity of the pipeline under the internal pressure and high temperature are analyzed.The influence of different boundary conditions is considered in the analysis.Considering the degradation of the maximum allowable hoop strain and elastic modulus of the composite material,and the influence on the load carrying capacity of the composite material repaired pipeline is analyzed.According to related test results and design requirements,the decrease of maximum allowable hoop strain of composites due to the degradation of matrix properties is analyzed.The influence of material degradation is taken into account in the design of the composite repair system,and the variation of design parameters is analyzed,which could provide some value for the design of composite repair system. |
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