剪跨比对CFRP加固RC剪力墙抗剪承载力及加固效率影响分析

EFFECT OF SHEAR SPAN RATIO ON SHEAR BEARING CAPACITY AND ON STRENGTHENED EFFICIENCY OF CFRP-STRENGTHENED RC SHEAR WALLS

为探究剪跨比对外贴碳纤维增强聚合物(CFRP)布加固钢筋混凝土(RC)剪力墙抗剪性能及破坏机制的影响规律,建立了考虑Hashin损伤准则及Cohesive内聚力作用的三维数值模型。利用已有的试验数据验证了该文数值模拟方法的准确性,研究了剪跨比对不同加固方式下剪力墙的破坏模式、抗剪承载力和延性系数等力学性能的影响,并进一步分析了剪跨比及加固方式对CFRP抗剪贡献及加固效率的影响规律。结果表明:随着剪跨比的增大,CFRP加固RC剪力墙的抗剪承载力降低,CFRP的抗剪贡献与加固效率被大幅削弱;此外,在同一剪跨比下,相较于双面加固及全包裹加固方式,采取水平条带加固剪力墙将提高1.0倍~3.0倍的抗剪承载力加固效率,延性系数提高效率增大0.8倍~2.4倍。

To investigate the influence mechanism and law of shear span ratio on the shear resistance and failure mechanism of CFRP(carbon fiber reinforced polymer)strengthened RC(reinforced concrete)shear wall,a threedimensional numerical model of CFRP-strengthened RC shear wall was established,considering the Hashin damage criterion and the Cohesive model.Firstly,the accuracy of the numerical simulation method was verified by the existing experimental data.Then,the failure modes,shear bearing capacity,and ductility coefficient of CFRP-strengthened RC shear wall under different shear span ratios and CFRP wrapping methods were studied.Further,the influence law of shear span ratio and wrapping method on the CFRP shear contribution and strengthened efficiency were analyzed.The results show that:with the increase in shear span ratio,the shear bearing capacity of CFRP-strengthened RC shear wall decreases,and the CFRP shear contribution and the strengthened efficiency were significantly weakened.Additionally,under the same shear span ratio,RC shear walls strengthened by horizontal strips will improve the efficiency of shear strength by 1.0~3.0 times,and the improved efficiency of ductility coefficient was increased by 0.8~2.4 times,compared with double-sided and fullwrapped strengthened methods.