FRP筋混凝土界面的疲劳粘结性能及寿命预测方法研究

发布时间：2018-04-29 12:28

本文选题：CFRP + RPC　；参考：《长沙理工大学》2015年硕士论文

【摘要】：纤维增强复合材料FRP(Fiber Reinforced Polymer/Plastic)筋以其强度高、重量轻、免锈蚀和抗疲劳性能好等优异性能极有希望成为处于恶劣自然环境下混凝土结构中传统钢筋的潜在替代品。FRP筋与混凝土能否正常工作,两者的界面粘结性是关键的技术问题。目前国内外针对FRP筋混凝土界面静力粘结性能研究已取得丰富的成果,而针对FRP筋混凝土界面的疲劳粘结性能研究较少,为了使其研究成果进一步完善,对FRP筋混凝土界面的疲劳粘结性能及相应的寿命预测值具有重大的实用价值。本文依托国家自然科学基金资助项目对FRP筋活性粉末混凝土(RPC)界面的疲劳粘结性能进行了试验研究。主要的研究内容及其相应的研究成果如下:(1)根据常幅荷载作用下CFRP筋混凝土界面疲劳性能的试验研究,得到荷载循环次数、锚固长度、应力水平和应力幅值对CFRP筋粘结式锚具组装件的荷载滑移曲线和钢套筒应变的影响,探究了疲劳荷载对CFRP筋轴向动应变的影响,对比了疲劳前后粘结式锚具组装件静载试验的破坏形式、极限承载力、荷载滑移曲线、CFRP筋刚度和钢套筒应变等,最后得到了疲劳寿命预测曲线和临界锚固长度计算式。(2)结合公路桥梁的随机变幅疲劳荷载谱,研究了随机疲劳荷载作用下CFRP筋混凝土界面的疲劳性能,得到荷载循环次数和锚固长度对对粘结式锚具组装件的荷载滑移曲线和钢套筒应变的影响,探究了随机循环疲劳荷载对CFRP筋轴向动应变的影响,通过随机疲劳后的静载试验对比了疲劳前后粘结式锚具组装件的破坏形式、极限承载力、荷载滑移曲线、CFRP筋刚度和钢套筒应变等,最后得到了随机疲劳寿命预测曲线、临界锚固长度计算式和CFRP筋的疲劳损伤演化规律。(3)采用ANSYS对粘结式锚具组装件的疲劳性能进行了分析。研究了锚固长度、应力水平和应力幅值对组装件疲劳寿命的影响,对比试验结果在一定程度上验证了该理论分析的正确性。
[Abstract]:Fiber reinforced composite FRP(Fiber Reinforced polymer / plastic tendons are high in strength and light in weight. It is very promising to be a potential substitute for the traditional reinforcement in the harsh natural environment. The interfacial bond between the FRP bars and the concrete is a key technical problem. At present, the research on the static bond behavior of FRP reinforced concrete interface has made a lot of achievements at home and abroad, but there are few researches on the fatigue bond performance of FRP reinforced concrete interface, in order to further improve the research results. It is of great practical value to the fatigue bond performance and the corresponding life prediction value of FRP reinforced concrete interface. In this paper, the fatigue bond properties of FRP reinforced reactive powder concrete (RPC) interface are studied with the aid of National Natural Science Foundation. The main research contents and corresponding research results are as follows: (1) based on the experimental study of the interface fatigue behavior of CFRP reinforced concrete under constant amplitude loading, the load cycle times and anchoring length are obtained. The effects of stress level and stress amplitude on the load-slip curve and the steel sleeve strain of the CFRP bar bonded Anchorage assembly are investigated. The effect of fatigue load on the axial dynamic strain of the CFRP bar is investigated. The failure modes, ultimate bearing capacity, load slip curve, CFRP bar stiffness and steel sleeve strain of bonded Anchorage assembly before and after fatigue are compared. Finally, the fatigue life prediction curve and the critical Anchorage length formula are obtained. Combined with the random variable amplitude fatigue load spectrum of highway bridges, the fatigue behavior of CFRP reinforced concrete interface under random fatigue load is studied. The effects of load cycle times and anchoring length on load-slip curve and steel sleeve strain of bonded Anchorage assembly are obtained. The effect of random cyclic fatigue load on axial dynamic strain of CFRP bars is investigated. The failure form, ultimate bearing capacity, load slip curve, CFRP bar stiffness and steel sleeve strain of bonded anchors before and after fatigue were compared by static load test after random fatigue. Finally, the prediction curve of random fatigue life was obtained. The critical Anchorage length and fatigue damage evolution of CFRP bars are calculated. The fatigue behavior of bonded Anchorage assembly is analyzed by ANSYS. The effects of anchoring length, stress level and stress amplitude on the fatigue life of the assembly are studied. The correctness of the theoretical analysis is verified to some extent by comparing the experimental results.
【学位授予单位】：长沙理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TU528

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