【作者】 袁菁颖；

【导师】 王春江； 李向民；

【作者基本信息】 上海交通大学 ， 结构工程， 2011， 硕士

【摘要】 纤维复合材料(FRP)以其轻质高强、耐腐蚀、施工性能好等优越性能在工程加固中应用普遍,并开始以各种形式应用到各类土建结构工程中,目前主要用于加固混凝土结构。国内外有相关人员对碳纤维(CFRP)加固钢结构进行了研究,但是仅对CFRP加固钢梁和组合梁进行了部分试验研究和理论分析,缺乏基于试验验证的大量的系统化的精细有限元分析和模拟,以及对其在各种构件参数和材料参数下的构件承载力状态进行系统化研究。对其开裂强度模型,塑性状态下的开裂机理,破坏模式和参数等方面的研究也不够。本文对CFRP加固H型钢梁进行了两组对比试验;结合断裂力学提出三种试验计算模型,通过模型和试验比较,确定模型破坏参数;并采用其中一种模型进行了参数分析。所做工作包括:1、在查阅国内外文献的基础上,总结前人所做的理论与试验研究,提出课题的研究目的和主要内容。了解粘结过程,归纳各种粘结强度模型。2、对不同加载方式和不同加固模式下的CFRP加固H型钢梁进行了两组比较试验,并对试验结果进行了综合分析。通过对试验结果的比较分析,给出了各种加固方式下的钢梁的极限承载力变化及CFRP布和钢梁的各项力学性能和详细数据。并通过对试验结果的比较分析,得出了一些具有工程指导意义的结论。3、比较已有模型的优缺点,结合断裂力学理论,提出用内聚力接触、内聚力单元、扩展有限元模拟界面开裂,对比试验结果,确定模型破坏参数。4、在ABAQUS中用内聚力接触模型进行数值模型参数分析,比较模型高跨比、CFRP粘贴量、加载方式对钢梁极限承载力、CFRP布有效粘结长度和粘结正应力、粘结剪应力的影响,对考虑塑性变形的极限状态设计给予指导。更多还原

【Abstract】 Fiber reinforced polymer (FRP) has been greatly used in engineering because of its low weight, high qualities in strength, anti-corrosion and construction. It is being used in civil and structural engineering in all kinds of shapes, and mainly for concrete strengthening. Researchers from home and abroad have made researches on steel structures strengthened with carbon fiber reinforced polymer (CFRP), but they just did some experimental researches and theories on steel beams or composite beams strengthened with CFRP. There is lack of systematic experimental and FEM analysis. The analysis of crack intensity model and interfacial crack mechanism in plasticity is still not enough.In this paper, we compared experiments of H-shaped beams strengthened with CFRP, and raised three models combined with Fracture Mechanics for simulation. We defined parameters of fracture mechanism comparing the results of simulation with experiment, and made parameter analysis using one of the three models. The whole work is as follows:1 We made conclusions of formal theoretical and experimental researches by referring to papers, made sure of the research targets and main contents; got knowledge of cohesion period and the formal cohesive models.2 We compared experiments of H-shaped beams bonded with CFRP in different loading conditions and different reinforced methods and gave out details such as ultimate bearing capacity and the specimens’mechanical properties by comparing test with analysis. Through the compared test results’ analysis, we presented some useful conclusions in engineering applications.3 We compared formal FEM models, used cohesive surface, cohesive element and XFEM to simulate the interfacial combined with Fracture Mechanics, made sure of damage parameters by comparison with experimental results.4 We used cohesive surface in ABAQUS to do parameter analysis, compared the influence made by different beam depth-span ratio, length of CFRP and loading conditions to CFRP’s effective length, interfacial normal and shear stress. We presented some useful conclusions of ultimate situation in plasticity.更多还原