波形齿夹具张拉CFRP 带的力学性能试验研究及夹具体系设计

对波形齿夹具在张拉CFRP 带时的受力状态的分析,理论上提出了CFRP 带理论伸长值的修正以及波形齿夹具配套螺杆的轴力、剪力验算。针对这3 个方面的问题,共设计了两大类试验来研究张拉CFRP 带时的波形齿夹具:一类是钢梁台座上仅张拉CFRP 带的试验；另一类是张拉CFRP 带加固钢筋混凝土T 形梁的试验。试验表明:以折减率来考虑波形齿夹具张拉CFRP 带的理论伸长值的修正；在张拉时螺杆轴力与CFRP 带的预拉力值呈定值比例,在工程实际中可以通过螺杆轴力值对CFRP 带预拉力值的监控。并提出了单个螺杆的轴力值与剪力值的计算公式。

EXPERIMENTAL RESEARCH ON MECHANICAL PROPERTY OF PULLING CFRP BELT WITH WAVE-SHAPED-GEAR CLAMP AND DESIGN OF CLAMP SYSTEM

Based on the analyses of the stress of a pulling CFRP belt with a wave-shaped-gear(WSG) clamping,this paper theoretically proposes the modification in the theoretical elongation of the CFRP belt and the computation of the axial and shear forces in the screw bolt of the WSG clamping.Aimed at those three problems,two types of experiments are designed to study the WSG clamping for a pulling CFRP belt.One type test is only pulling a CFRP belt on a steel beam dado;another type test is a reinforced concrete T-beams strengthened with a pulling CFRP belt.The results of tests indicate that the reduction factor can be used to evaluate the modification of theoretical elongation in a CFRP belt under pulling with a WSG clamping;when the CFRP belt is pulled with a WSG clamping,the ratio of the axial force of the screw bolt to the pulling force of the CFRP belt is fixed,which can be used to monitor the pulling force of the CFRP belt in existing strengthening methods.The design shear force and design axial force of the single screw bolt are proposed in this paper as well.