碳纤维增强复合材料黏结型锚固体系弯拉性能试验研究

Experimental Study on CFRP Bonded Anchorage Systems Under Combined Tension and Bending

为了研究碳纤维增强复合材料(CFRP)黏结型锚固体系的弯拉性能,对设计的锚固体系试件进行了10组轴向拉伸试验与12组弯拉试验。在锚固体系优化基础上研究了CFRP筋直径、弯曲半径改变下试件的极限承载力、破坏模式、锚固效率及CFRP筋荷载‒应变关系。结果表明,锚固体系的弯拉承载力折减量系数随CFRP筋弯曲半径的增大而减小,CFRP筋直径越大试件承载力折减量系数越大,并且CFRP筋横向约束有利于弯拉极限承载力的提高。此外,CFRP筋荷载‒应变曲线的非线性变化是试件失效前的典型特征。弯曲半径和CFRP筋直径的比值与锚固效率系数为线性关系,比值在2.4‰以下时试件的弯拉锚固效率系数小于80%,试件呈不均匀断裂和剪切的破坏形式。

Ten axial tensile tests and twelve combined tension and bending tests were conducted on the designed anchorage system specimens to investigate the mechanical properties of the carbon fiber reinforced polymer(CFRP)bonded anchorage system under combined tension and bending.Based on the optimization of the anchorage system,the ultimate bearing capacity,failure modes,anchorage efficiency,and CFRP tendon load-strain relationship of the specimens were studied with CFRP diameter and bending radius changes.The results indicate that the tensile strength reduction coefficient of the anchorage system decreases with the increase of CFRP tendon bending radius,and the larger the CFRP tendon diameter,the greater the reduction coefficient of specimen bearing capacity.The transverse constraint of CFRP tendons contributes to the improvement of tensile strength with bending.Additionally,the nonlinear variation of the load-strain curve of CFRP tendons is a typical characteristic before specimen failure;the ratio of bending radius to CFRP tendon diameter shows a linear relationship with the anchorage efficiency coefficient,and when the ratio is below 2.4‰,the anchorage efficiency coefficient of the specimen is less than 80%,exhibiting failure modes of non-uniform fracture and shear.