【作者】 李强；

【导师】 王振宇；

【作者基本信息】 浙江大学 ， 水工结构工程， 2016， 硕士

【摘要】 钢制管道作为常见的运输方式,广泛应用于石油、天然气等的输送,在服役期间,不可避免会遭受腐蚀、撞击、爆炸等外部环境及荷载作用,造成管道各种不同的缺陷和损伤,进而引发重大安全事故,造成财产损失和人员伤亡。为了避免事故的发生和保证管道安全运行,FRP加固钢管构件作为一种新的加固技术被国内外专家学者广泛关注。本文研究了CFRP加固钢板的界面粘结性能,开展了静力作用下CFRP加固钢管的数值模拟,通过试验和数值模拟研究了落锤低速冲击作用下FRP加固圆钢管的破坏情况。具体研究内容总结如下：(1)开展了单剪试验结果的数值模拟验证,界面模拟采用双线性模型,得到了试件的界面剪应力-滑移曲线和荷载-位移曲线,经分析比较,试验结果与模拟结果吻合较好。讨论了CFRP长度、粘结剂厚度以及界面断裂能对粘结效果的影响。(2)开展了CFRP加固缺陷钢管在静力受拉和受弯情况下的数值模拟,得到了加固前后钢管的应力结果,对加固效果进行了评估,对内压、外部荷载及加固厚度等参数进行了分析。(3)开展了CFRP加固圆钢管的低速横向冲击试验,对全过程冲击力的变化进行了数据采集,并得到了不同情况下复合管道的破坏模式。对CFRP加固圆钢管冲击过程进行了数值模拟,获得了冲击荷载下管道沿轴向的整体挠度变形和局部凹陷变形,讨论了CFRP粘贴层数、冲击速度以及管道缺陷等因素的影响。更多还原

【Abstract】 As a common method of transportation, steel pipes are widely used in petroleum, natural gas, etc. During the period of service, they will inevitably suffer from corrosion, impact, explosion and damage, causing serious safety accident, property damage and loss of lives. In order to avoid the accidents and ensure the safe operation of the pipelines, and steel tubes strengthened by FRP as a new technology has been paid more attention by domestic and foreign experts or scholars. In this paper, experiments and numerical simulations were carried out to investigate the interfacial bonding properties of FRP reinforced steel structure, and the damage of the FRP bonded steel tubes which subjected to the hammer impact with low velocity. Specific contents of this study are summarized as follows:(1) Numerical simulation validations of single shear tests were carried out, and the bilinear model was used to simulate the interface between steel and CFRP. Interfacial shear stress-slip curves and load-displacement curves were obtained. The FE results are in good agreement with the experimental ones. And the influence of the FRP length, thickness and interfacial fracture energy of adhesive are also taken in consideration.(2) Numerical simulations of the CFRP reinforced defect steel tubes were conducted in static tension and in bend. The reinforcement were evaluated by the comparison of stress variation of steel pipes before and after strengthened. The internal pressure, external load and the thickness of reinforcement have also been analyzed.(3) Experiments of round steel pipes bonded with CFRP subjected to drop hammer impacts in low-velocity were carried out, and the whole processes of impact loads and damages were obtained. The dynamic responses and failure modes of CFRP reinforced circular pipes were numerically simulated. The deformations of the pipes under the impact load were acquired. The influences of CFRP layers, impact velocity and minor defects upon impact resistance were discussed.更多还原