CFRP 纤维布加固RC 柱的有限元分析模型
FINITE ELEMENT ANALYTICAL MODELS FOR REINFORCEDCONCRETE COLUMNS REINFORCED WITH CFRP SHEETS
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摘要: 为了建立统一的碳纤维(CFRP) 布加固钢筋混凝土(RC) 柱的抗震性能的评价手段, 基于二维有限元分析研究探讨分析模型; 对3 个CFRP 布加固RC 柱进行了2D-FEA 参数模拟分析, 考察了现存的裂缝模型、材料本构关系、混凝土的压缩模型对分析结果的影响。通过分析比较得出, 混凝土使用Darwin-Pecknold 的等价一轴应变模型能很好地模拟CFRP 布加固的RC 柱的非线性特性及其强度; 而且修正Kent-Park 模型能够较好地模拟箍筋、CFRP 布对混凝土的横向约束作用, 同时Darwin 的破坏准则可以较好地评价二轴应力下混凝土的破坏过程。通过考察CFRP 布加固的RC 柱的荷载-变形关系、柱子反弯点和柱脚处混凝土、钢筋和CFRP 的应力-应变的发展, 进一步证实了CFRP 布对RC 柱的抗震加固十分有效。Abstract: In order to build a uniform evaluating means of seismic ret rofitting performance of reinforced concretecolumns with CFRP sheet s , analytical models are studied through two-dimensional finite element analysis ( 2D-FEA) . Based on the paramet ric simulation of three RC columns st rengthened with CFRP sheet s , the applicabilityand availability of crack models , constitutive relationships on cracks and concrete compressive models are investigated. The result s show that Darwin-Pecknold’s equivalent uniaxial st rain model can be used to simulate the nonlinearbehavior and st rengthen effect of RC columns through comparing with test result s. The modified Kent-Park’s confinement model can be used to evaluate the influences on capacity of confinement effect s f rom hoop steels and CFRPsheet s , and Darwin’s failure criteria can be used to evaluate the concrete failure in a biaxial st ress state. Seismic retrofit ting performances of RC columns st rengthened with CFRP sheet s are verified by analyzing load2deformation relations and the processes of st ress-st rain at the inflection point and the foot of the columns.