碳纤维约束高强混凝土圆柱压弯构件非线性全过程分析  

Nonlinear analysis of carbon fiber sheets confined high strength concrete circular column subjected to axial load and lateral shear

作　　者：王震宇[1] 王代玉[1] 芦学磊[2] 

机构地区：[1]哈尔滨工业大学土木工程学院,哈尔滨150090 [2]天津水泥工业设计研究院有限公司,天津300400

出　　处：《计算力学学报》2009年第6期913-918,共6页Chinese Journal of Computational Mechanics

基　　金：国家自然科学基金(50408010);地震行业科技专项基金(200808073)资助项目

摘　　要：为分析塑性铰区碳纤维约束高强混凝土圆柱的抗震性能,编制了可得到荷载-位移曲线软化段的非线性全过程分析程序,保护层和箍筋约束混凝土采用Mander本构模型,碳纤维约束混凝土采用ACI 440.2R-08给出的本构关系,将程序计算结果与试验结果进行比较,两者吻合较好;利用该程序分析了轴压比、混凝土强度、碳纤维包裹长度及层数、纵筋配筋率等参数对碳纤维约束混凝土圆柱荷载-位移关系的影响规律,结果表明:当轴压比超过0.55后,柱构件的水平承载力开始降低,柱的破坏形式由延性的受拉破坏向脆性的受压破坏转变;剪跨比大于3的圆柱,碳纤维在塑性铰区包裹长度大于1.2倍柱直径时,即可达到与全柱包裹基本一致的效果;对混凝土强度为50 MPa^80 MPa的高强混凝土圆柱,以包裹3~4层碳纤维为宜;随着纵筋配筋率的增加,柱的水平极限承载力及延性均有所提高。To analyze the seismic behavior of high strength concrete circular columns confined with carbon fiber sheets （CFS） in the plastic hinge region, a nonlinear analytical procedure was developed, which can obtain the descending branch of shear-tip deformation curves of columns subjected to axial load and lateral shear. The Mander stress-strain model was used for concrete confined with hoops and for unconfined concrete cover. The stress-strain model proposed by ACI 440.2R-08 was used for FRP- confined concrete. The numerical simulation results agree well with experimental results. Influences of axial compression ratio, concrete strength, height and layers of CFS wrapping, longitudinal reinforcement ratio on shear-tip deformation curves were analyzed using this procedure. The results indicate that the lateral loading capacity of columns begins to and the failure mode of columns transfers from decrease when the axial compression ratio exceeds 0.55, ductile tensile failure to brittle compressive failure. For columns with shear span ratio greater than 3.0, when the height of wrapped CFS in the plastic hinge region exceeds 1.2D （D is the diameter of circular column）, the seismic performance can be improved to a level equivalent to full CFS-wrapped columns. For high strength concrete from 50MPa to 80MPa, three or four layers of CFS wrapping are reasonable. With an increase of the longitudinal reinforcement ratio, the shear capacity and ductility level of columns show a corresponding enhancement.

关 键 词：碳纤维 约束混凝土 高强混凝土 圆柱 非线性分析 

分 类 号：TU375.3[建筑科学—结构工程]