含腐蚀缺陷的管道静力性能试验测试研究

为研究腐蚀缺陷对管道承载力的影响,本文分别进行了含腐蚀缺陷管道在轴压载荷、弯曲载荷以及轴压和弯曲复合载荷作用下的静力失效过程测试。通过不同载荷作用下管道的荷载-位移曲线以及荷载-应变曲线来分析管道的失效模式和失效机理;通过有限元分析结果与试验测试结果验证其准确性。结果表明:腐蚀缺陷使管道在三种不同荷载作用下的极限承载力均有所下降;针对文中所研究的管道及其腐蚀缺陷,在轴压载荷作用下管道承载力下降了18.4%,在弯曲载荷作用下管道承载力下降了20.96%,在轴压和弯曲复合载荷作用下管道承载力下降了13.3%;管道中腐蚀缺陷位置的管壁厚度减小,该位置应变发展迅速,首先进入塑性屈服状态,最终导致该腐蚀位置发生弹塑性屈曲失效。

Static tests on corroded pipelines

Corrosion defects occur easily on the surface of pipelines due to the severe servicing environment,and it is one of the key factors to cause the failure of pipeline.To ensure the safety of the service pipelines,it is very important to study the load carrying capacity and the service life of pipelines.To study the influence of corrosion defects,static tests on failure process of corroded pipelines under axial compressions,bending moments andcombined loadings of compression and bending are carried out,respectively.The load-displacement curves and the load-strain curves of the specimens under above three different loads are plotted to analyze the failure mode and the failure mechanism.The accuracy is verified by comparing the finite element analysis results with the test results.Results show that corrosion can reduce the load carrying capacity of pipelines.For the designed specimens with corrosion defects,the load carrying capacities decrease by 18.4%for the specimen under axial compressions,20.96%for the specimen under bending moments,and 13.3%for the specimen under combined load of axial compressions and bending moments,respectively.The tube-wall thickness at the corroded location of the pipeline reduces and the strains at this location develop quickly.The location at corrosion yields firstly to cause an elastic-plastic buckling failure.