预拉碳纤维布加固持荷混凝土梁受力性能分析

Mechanical Behavior of Preloaded Reinforced Concrete Beams Strengthened by Pretensioned Carbon Fiber Composite Sheets

摘要:

根据预张拉碳纤维布加固持荷钢筋混凝土梁受力特点,采用商业软件建立有限元模型对梁加固和受荷全过程进行模拟和分析.对两组试验梁的模拟计算结果显示,有限元方法有较好的精度.试验和进一步的有限元数值模拟分析结果表明,当构件上的持荷水平超过未加固构件承载力的40%时,持荷会降低加固构件的承载力；采用预张拉加固方法可充分发挥碳纤维布的强度,当碳纤维布中的有效预拉应变达0.003~0.004时,可消除持荷对加固梁受力性能的影响.

Abstract:

According to the characteristic of preloaded reinforced concrete beams strengthened by pretensioned carbon fiber composite sheets,a suitable finite element model and corresponding calculation steps were proposed.The method was verified by the testing results of two groups of strengthened beam specimens.Comparison between simulation and testing results shows that the proposed method is a precise numerical tool.Further parameter analysis using the proposed method shows that the bearing capacity of a strengthened beam might be notably reduced if the preload applied on the beam is larger than 40% of the initial bearing capacity of the beam,the strength of carbon fiber composite sheets can be fully used by using pretensioning technique,and the negative influence of the preload on the bending behavior of a strengthened beam can be made up when the prestrain of carbon fiber composite sheets is between 0.003~0.004.