Study Of The Strength Of Corroded Pipeline Repaired By Composite Materials

Pipeline corrosion is one of the most important reasons leading to pipeline damage,especially in complex loading for a long time under the condition of buried pipeline or seabed pipeline.As many scholars and experts come to the development of pipeline repair technology,composite materials are increasingly used on pipeline repair because of the short time,simple technology and low repair costs.To understand the pipeline repair technology with composite material deeply,this paper uses a new type of the finite element model to study the pipeline strength and failure mechanism,which is vertified by the tensile test of corroded pipeline repaired by glass fibre composite materials.(1)In this paper,the failure mode of the composite repaired pipeline under tensile loading is studied,and the test results are used to verify the accuracy of the finite element model.(2)This paper establishes a new finite element model to simulate the debonding phenomenon between the composite layer and corrosion pipeline by introducing the Cohesive bonding element.Write an ABAQUS subroutine to define composite Hashin strength failure,which can simulate the failure of the composite layer.The ultimate load and failure mechanism of composite repaired pipeline under different loads are studied by the new model.(3)The stress distribution of the composite material repair layer under the internal pressure is analyzed through multi-layer management theory.According to the composite failure criterion,the minimum thickness of corrosion pipeline repair is caculated.(4)There is a comparison between the he theoretical analysis and finite elemen,which respectively study on composite layer laying angle arrangement,composite layer thickness and composite layer length on the repair effect,so as to optimize the design of the composite layer repair parameters.