表层嵌贴CFRP板条加固RC梁刚度性能研究

Study on Stiffness Behaviour of RC Beams Strengthened by NSM CFRP Strips

利用ABAQUS有限元软件模拟已有试验梁来研究二次受力下表层嵌贴CFRP板条加固RC梁的正常使用阶段的性能,并将有限元计算结果和试验结果对比,验证建立模型的正确性和有效性。利用验证后的模型进一步做二次受力下加固梁正常使用阶段刚度的影响因素分析,结果表明持载加固梁的预加载程度、配筋率和板条加固量对刚度影响较大。根据普通钢筋混凝土梁的刚度理论,采用曲率理论推导了考虑二次受力的表层嵌贴CFRP板条加固梁的正常使用阶段的刚度计算公式,并利用试验数据进行了验证分析,表明本文建立的刚度公式偏于安全,为后续研究刚度性能提供一定的参考。

ABAQUS finite element software is used to simulate existing test beams to study the stiffness behaviour of RC beams strengthened by NSM CFRP strips under the secondary load,experimental results and calculation results of finite element are compared to verify the correctness and validity of the model.Based on the model,the influence factors of the stiffness of the strengthened beam under the secondary load are analyzed,The results show that the preloading degree of the beam,reinforcement ratio and the number of the strips have great influence on the stiffness.According to the theory of stiffness of reinforced concrete beams,curvature theory is applied to deduct the normal service stage stiffness formula of RC beams strengthened by NSM CFRP strips under the secondary load,and formula is verified by test data,It is shown that the stiffness formula established in this paper is conservative,which provides a reference for the follow-up study of stiffness behaviour.