U型FRP加固钢筋混凝土梁受剪剥离性能的有限元分析

FINITE ELEMENT ANALYSIS OF SHEAR BEHAVIOR OF RC BEAMS STRENGTHENED WITH U-SHAPED FRP SHEETS

采用FRP布对梁进行抗剪加固,可以有效的解决梁因配箍率不足而导致的受剪承载力偏低的问题。根据文献[1]中7根试验梁的参数,针对工程中常用的U型FRP受剪加固形式,建立三维有限元分析模型,采用商业有限元计算软件ANSYS,数值模拟了加载全过程和受剪剥离受力性能,根据试验结果确定了FRP-混凝土界面粘结剥离强度,并建议了合适的裂面剪力传递系数。根据有限元分析结果,作者又进一步研究了U型FRP布的应变分布、分担剪力的贡献、剥离破坏的过程,以及加固量、FRP类型和粘贴面积率对加固梁受剪承载力的影响。在有限元分析的基础上结合试验结果,建议了U型粘贴加固的受剪剥离承载力计算方法。

The utilization of FRP in shear strengthening for reinforced concrete beams is an effective way in upgrading the low loading capacity of the beams. Based on the test data of seven beams, this paper presents analysis of FRP strengthened RC beams using 3-D finite element model which is implemented in ANSYS. The effects of various parameters on numerical results are discussed. The bond strength between FRP and concrete, shear retention coefficients for cracks are determined. The results are in good agreement with the experimental results. To gain a better understanding of the role that FRP plays in the RC beam shear strengthing, further investigation is conducted in regard to the distribution of strain in FRP under each load level, the FRP＇s contribution to the overall shear strength, the peeling-off process of FRP from the concrete＇s surface and the relationship between the efficiency and the amount of FRP used in the shear strengthing.