Analysis of the interfacial stresses of the strengthened rc beams externally bonded with cfrp sheet or steel plate

Abstract

钢筋混凝土梁可采用外贴碳纤维或钢板条于梁底的方法进行补强加固。但是 ,在板条与梁底间的粘结界面端部将产生较大的沿粘结面的剪应力和垂直粘结面的正应力 ,这些应力将有可能造成外贴板条端部锚固失效 ,从而 ,使梁因板条的材料强度得不到充分发挥而提前破坏。目前 ,已有的计算界面应力公式都是在弹性理论基础上假定应力沿胶层厚度为常量 ,并且 ,忽略了板条端部的应力奇异现象而得到的。为此 ,对该类加固梁的胶层应力分布 ,特别是板条端部的应力 ,采用LUSAS有限元分析程序进行了详细的计算研究 ,对影响胶层应力分布的主要因素也进行了分析研究 The reinforced concrete(RC) beams can be strengthened by externally bonding carbon fiber reinforced polymer(CFRP)sheets or steel plates on their tension faces;however much large shear and normal stresses along the adhesive line at the plate end will occur.These stresses may cause the plate debond at its end and the strengthened beams fail prematurely.The available calculation for the interfacial stresses is established on the basis of the elastic theory, assuming the stresses over the depth of the adhesive as constants.In this paper,the finite element analysis software LUSAS was applied to study the stress distribution among the adhesive layer including the interfacial stresses,especially focus on the ultimate stresses at the plate end.Furthermore,the main factors affecting the peak values of the interfacial stresses were also investigated entirely.