复杂载荷作用管道腐蚀缺陷剩余强度非线性有限元研究

发布时间：2018-05-20 15:46

本文选题：复杂载荷 + 剩余强度　；参考：《西安石油大学》2017年硕士论文

【摘要】：作为一个能源消耗大国,我国也越来越重视石油天然气运输管道的建设。长期埋于地下的压力管道会发生不同程度的腐蚀,含腐蚀缺陷的埋地管道直接与管体周围土壤接触,会受到复杂的外载荷。本文以X80级钢材的压力管道为研究对象,采用有限元分析的方法,研究了缺陷深度、长度和宽度这三个因素在纯内压、内压和弯矩组合作用以及内压和轴向力组合作用下对管道的失效压力的影响,主要研究成果如下:(1)建立了含单个腐蚀缺陷管道的三维非线性有限元模型,通过与真实腐蚀管道爆破实验结果和文献计算结果的对比,验证了含腐蚀缺陷管道有限元模型的准确性。(2)通过对腐蚀管道分别施加纯内压,内压和弯矩以及内压和轴向力得到的等效应力云图可知,在这三种力的组合形式中,腐蚀管道发生失效的位置均处于腐蚀缺陷区域的中心位置。(3)腐蚀管道在内压,内压和弯矩以及内压和轴向力作用下,管道失效压力均随缺陷轴向长度的增大而降低,且降低的速率越来越缓慢。其中在内压作用时,管道的失效压力在缺陷长度约250mm以后趋于一个定值,而在内压和弯矩以及内压和轴向力的作用下,管道的失效压力在缺陷长度为250mm处仍处于下降趋势。说明复杂载荷对腐蚀管道缺陷的失效压力在改变缺陷长度下的变化规律有一定的影响。
[Abstract]:As a big energy consuming country, our country pays more and more attention to the construction of oil and gas transportation pipeline. The pressure pipeline buried in underground for a long time will be corroded to varying degrees. The buried pipeline with corrosion defects will come into contact with the soil around the pipe body directly and will be subjected to complex external loads. In this paper, the pressure pipeline of X80 grade steel is taken as the research object, and the three factors of defect depth, length and width in pure internal pressure are studied by using finite element analysis method. The effect of internal pressure and bending moment combination and internal pressure and axial force on the failure pressure of pipeline is studied. The main research results are as follows: 1) the three-dimensional nonlinear finite element model of pipeline with single corrosion defect is established. The accuracy of finite element model of corroded pipeline with corrosion defects is verified by comparing with the experimental results of real corroded pipeline blasting and the results of literature calculation. (2) the pure internal pressure is applied to the corroded pipeline respectively. The equivalent stress cloud diagram obtained from internal pressure and bending moment and internal pressure and axial force shows that in the combination of the three forces, the failure position of the corrosion pipeline is located at the center of the corrosion defect area. Under the action of internal pressure, bending moment, internal pressure and axial force, the failure pressure of pipeline decreases with the increase of the axial length of the defect, and the rate of reduction becomes slower and slower. Under internal pressure, the failure pressure of pipeline tends to a fixed value after the defect length is about 250mm, but the failure pressure of pipeline is still decreasing when the defect length is 250mm under the action of internal pressure, bending moment, internal pressure and axial force. It is shown that the complex load has a certain influence on the failure pressure of corrosion pipeline under varying the length of the defect.
【学位授予单位】：西安石油大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TE988.2

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