管道体积型缺陷复合材料补强的试验模拟研究  

Reinforcement of defected pipeline by composite materials-investigations by hydrostatic test and numerical simulation

作　　者：王言聿 成志强 郑策 Wang Yanyu;Cheng Zhiqiang;Zheng Ce(Applied Mechanics and Structure Safety Key Laboratory of Sichuan Province,Department of Applied Mechanics,Southwest Jiaotong University,610031,Chengdu,China;PETROCHINA West-to-East Gas Pipeline Company,510665,Guangzhou,China)

机构地区：[1]西南交通大学力学与工程学院应用力学与结构安全四川省重点实验室,成都610031 [2]中国石油西气东输管道公司,广州510665

出　　处：《应用力学学报》2020年第5期1876-1881,I0002,I0003,共8页Chinese Journal of Applied Mechanics

基　　金：教育部高等学校博士学科点专项科研基金资助项目“金属蜂窝挤压成形、烧结的数值模拟与实验研究”(20110184110017)。

摘　　要：为分析管道体积型缺陷屈服前后复合材料缠绕层分担载荷的差异,在材质为X60钢、外径为508mm、壁厚为8.7mm的管件上预制深厚比约为70%的体积型缺陷,并进行低压水压试验,分析缺陷及完整管壁在弹性阶段的应力分布特点。采用玻璃纤维复合材料补强管道缺陷再次进行试验,分析试验压力上升时,管道缺陷发生塑性变形的水压值及应变响应趋势;采用水压试验结果验证有限元模型的准确性后,应用数值模拟分析管件缺陷屈服前后复合材料作用的差异。研究表明:对含体积型缺陷的管道,缺陷区域在内压作用下形成局部弯矩;复合材料缠绕层可以有效抑制这一弯矩,使弹性阶段局部弯矩的最大降幅超过50%,提高了缺陷发生屈服的压力;缺陷区域屈服之后,复合材料缠绕层分担环向载荷,对缺陷管壁的局部鼓胀具有约束作用,使补强管道沿剩余壁厚的应力分布不均匀度降低,约为未补强管道的一半,提高了管道的承载能力。A series of hydrostatic tests have been carried out using a tubular specimen of X60 steel in the present paper to discuss distinctively the sharing of the hoop load of composite overwrap layers for the cases before and after yielding of the pipe defect. Dimensions of the specimen are 508 mm outer diameter and 8.7 mm wall thickness. A volumetric defect with depth of 70% of the wall thickness is prefabricated in the tube. The specimen is firstly pressurized to a relatively low pressure, for the purpose to compare the stress distribution in the defect and normal region before yielding. Then overwrapping of the glass fibers with resin reinforcement is applied. Then hydraulic pressure is increased gradually to get the pressure value for appearing of the plasticity. The response and tendency of strain evolution is observed. After accuracy of finite element models are justified by results of hydrostatic tests, the numerical simulation experiments are carried out. The different effects of reinforce layer before and afteryielding of the defected region in pipe are analyzed. Results of simulation and laboratory tests indicate that once the tube is pressurized, local bending effects exist in defected pipe wall, and composite reinforce layer diminishes local bending moment efficiently, about 50% decrease in elastic stage. The yield pressure of the defected pipe wall increases significantly. After defected pipe wall yields, composite reinforce layers can function as sharing of the hoop load, and reduction of bulging bending as well. The nonuniformity of the stress distribution along the residual wall thickness of the reinforced pipe is only about half of that of the unreinforced pipe, and the load carrying capacity of the defected pipe after reinforcement can be improved.

关 键 词：纤维增强复合材料 补强机理 水压试验 有限元方法 局部弯矩 

分 类 号：TE832[石油与天然气工程—油气储运工程]