摘要
埋地管道是远距离油气输送的主要方式之一。然而,由于长时间服役,复杂的土壤环境会导致埋地钢管产生以点蚀凹坑为主的腐蚀损伤,严重威胁压力管道的安全运行。纤维增强树脂基复合材料因其高弹性、高强度、抗腐蚀的优良性能常被用来修复缺陷管道。为了减小点蚀缺陷管道的内压载荷损伤,考察碳纤维复合材料对点蚀缺陷管道的补强效果,针对0°和90°铺层的T300-3K平纹碳纤维树脂基复合材料,开展了拉伸试验研究,结合拉伸断口的扫描电镜(SEM)分析探究了平纹碳纤维复合材料的失效形式;采用ANSYS有限元方法,研究了不同尺寸、轴向或环向分布的椭球形点蚀缺陷对管道应力状态的影响,分析了不同缺陷深度对碳纤维补强效果的影响。结果表明,T300-3K平纹碳纤维复合材料在0°和90°铺层方向的力学性能及微观形貌相近;其拉伸失效以碳纤维断裂与树脂基体开裂为主,伴随有少量的粘结界面失效;椭球形缺陷长短轴比值越小、相邻缺陷间轴向距离越大或环向距离越小,管道缺陷处应力越小,当两缺陷间距增大到一定程度时,管道缺陷处应力将接近单个缺陷管道;碳纤维补强效果随缺陷深度的增加逐渐提高,当相对深度为0.8时,管道应力降低19.24%,补强效果最好。
Buried pipeline is one of the main way of long-distance oil and gas transportation.However,due to the long service time,the complex soil environment will lead to pitting corrosion damage against the buried steel pipe,which seriously threatens the safe operation of the pressure pipeline.Fiber reinforced resin matrix composites are often used to repair defective pipelines because of their excellent properties of high elasticity,high strength and corrosion resistance.In order to reduce the internal pressure load caused damage,the reinforcement effect of carbon fiber composites on pitted defective pipes was investigated.The tensile test was carried out for T300-3K plain carbon fiber resin matrix composite with 0°and 90°layup,and its failure forms were explored combined with the SEM analysis of tensile fracture.The influence of ellipsoidal pitting defects with different sizes,axial or circumferential distribution on the stress state of the pipeline was studied by ANSYS finite element method,and the influence of different defect depth on the reinforcing effect of carbon fiber was analyzed.The results show that the mechanical properties and micromorphology of T300-3K plain carbon fiber composites are similar at 0°and 90°.The tensile failure is mainly caused by the fracture of carbon fiber and the cracking of resin matrix,with a small amount of bonding interface failure.The smaller the axial ratio of the ellipsoid defect,the larger the axial distance or the smaller the circumferential distance between adjacent defects,the smaller the stress at the pipeline defect.When the distance between two defects increases to a certain extent,the stress at the pipeline defect will approach that of individual defective pipeline.The reinforcing effect of carbon fiber gradually increases with the increase of defect depth.When the relative depth is 0.8,the pipe stress decreases by 19.24%and the reinforcing effect is the best.
作者
王琪
周云
WANG Qi;ZHOU Yun(Special Equipment Safety Supervision Inspection Institute of Jiangsu Province,Nanjing,Jiangsu 210036,China)
出处
《石油管材与仪器》
2023年第3期26-32,共7页
Petroleum Tubular Goods & Instruments
基金
国家市场监督管理局项目“埋地管道损伤评价及局部补强技术研究”(编号:MK2020036)。
关键词
承压管道
点蚀缺陷
碳纤维复合材料补强
有限元模拟
pressurized pipeline
pitting defect
carbon fiber composite reinforcement
finite element simulation
