预应力FRP片材增强RC梁的界面应力分析

粘贴预应力纤维增强复合材料(FRP)片材对土木建筑结构进行加固和修复,可以提高工程效率,改善构件的受力状况.文中从理论分析入手,推导了预应力FRP片材增强钢筋混凝土(RC)梁界面层的剪应力和正应力的计算公式,分析了预应力作用下FRP片材和混凝土之间的界面层的应力分布,并通过有限元对碳纤维簿板(CFL)增强RC梁作了数值实验验证,探讨了初始预应力施加量和CFL厚度对界面应力的影响.理论分析和有限元计算结果表明,当CFL两端无锚固、施加初始预应力为CFL抗拉极限强度的20%时,CFL有发生剥离的危险.

Analysis of Interfacial Stresses for RC Beams Strengthened with Prestressed FRP

Bonding prestressed fiber-reinforced polymer(FRP) plate to strengthen and repair civil engineering structures improves the working efficiency and the force conditions of structures.In this paper,formulae of the shears and normal stresses on the interfacial layer between the prestressed FRPs and the concrete members of strengthened reinforced concrete(RC) beams were deduced based on theoretical analyses,and the distributions of the interfacial stresses were analyzed.Then,by means of finite element method(FEM),numerical experiments were carried out to reveal the effects of initial prestress and CFL thickness on the interfacial stresses.It is shown from theoretical analyses and FEM results that there may arise the debonding of CFL from the concrete members when the initial prestress is 20% of the tensile strength and is loaded on the CFL without anchorage at the two ends.