碳纤维布加固管桁架节点的工程应用研究

Engineering Application of Tubular Truss Joints Strengthened with Carbon Fiber Reinforced Polymer Sheets

摘要:

以体育场屋盖圆钢管桁架节点为对象，开展了碳纤维（CFRP）布加固的工程应用研究，涉及CFRP布缠绕加固空间管节点的步骤策略、环境温度下CFRP布胶粘剂抗剪强度试验、钢管表面涂层对CFRP布胶粘剂粘结强度影响的试验、防火涂料在CFRP布上粘结强度的试验、CFRP布加固空间KT型管节点的受力性能试验。研究表明环境温度改变、钢管表面原有涂层都对胶粘剂的粘结强度有影响，CFRP布加固时须选择适用的胶粘剂，打磨掉钢管表面涂层，防火涂料可以在CFRP布上直接喷涂。相比未加固的KT型节点，CFRP加固的节点承载力和延性分别提升了24 %和25 %。CFRP布加固圆钢管相贯焊接节点是可行和有效的，当需要适度提升承载力时，是一个富有特色的选项。

Abstract:

This study explores the engineering application of carbon fiber reinforced polymer （CFRP） sheets reinforcement on circular hollow section （CHS） joints of a stadium roof. It investigates several aspects， including reinforcement strategies of CFRP wrapping multiplanar CHS joints， shear strength tests of adhesive for CFRP at different temperatures， influence of steel surface coatings on the bonding strength of adhesives， bonding strength tests of fire coatings-CFRP， and mechanical tests of CFRP reinforced CHS KT-joints. The results indicate that the change of environmental temperature and the original coatings on steel tube surfaces influence the bonding strength of adhesives. It is essential to select a suitable adhesive for CFRP reinforcement，and the original steel tube coatings should be removed. Fire coatings can be directly sprayed on the CFRP. Compared to the bare CHS KT-joint， the CFRP-reinforced CHS KT-joint exhibited a 24 % increase in load-bearing capacity and a 25 % increase in ductility. Reinforcing CHS welded joints with CFRP sheets proves to be a feasible and effective method， making it a distinct choice for situations where the load-bearing capacity requires moderate enhancement.