CFRP-木材界面黏结剪应力-滑移关系试验研究

Experimental study on the bond shear stress-slip relationship of CFRP-timber interface

为了深入研究碳纤维增强聚合物(CFRP)与木材黏结界面的力学性能,通过对30个(6组)CFRP-木材界面黏结试件的剪切试验,分析CFRP应变和界面黏结剪应力的发展规律,获得黏结剪应力-滑移关系曲线,探讨CFRP粘贴长度、宽度对界面黏结性能的影响。通过对试验结果的回归分析,提出了CFRP-木材界面黏结剪应力-滑移模型。试验结果表明:试件主要发生剪切破坏和剥离破坏,破坏前没有明显征兆,属于脆性破坏;CFRP的粘贴宽度对界面的极限承载力的影响显著,超过一定长度后,粘贴长度对界面的极限承载力影响不明显;文章中提出的由两个参数控制的多项式-对数正态函数本构模型,能够较好地与试验结果相吻合;可为CFRP加固木结构提供理论依据和实践参考。

In order to study the mechanical properties of carbon fiber reinforced polymer(CFRP) and timber bonding interface, through the shear test of 30(6 groups) CFRP-timber double-sided bonding specimens, the development law of CFRP strain and interface bonding shear stress was analyzed, to obtain the bonding shear stress-slip relationship curve, and explore the effect of CFRP paste length and width on the interface bonding performance. Through regression analysis of the test results, the CFRP-timber interface bonding shear stress-slip constitutive relationship model is proposed. The test results show that the specimens mainly undergo shear failure and peeling failure, and there is no obvious sign before failure, which is brittle failure. The bonding width of CFRP has a significant influence on the ultimate bearing capacity of the interface. After a certain length, the bonding length has the limit of the interface. The bearing capacity is not obvious;the polynomial-lognormal function constitutive model controlled by two parameters proposed in the article can better fit the test results;it can provide a theoretical basis and practical reference for CFRP-reinforced wooden structures.