Abstract Ductile adhesives are more appropriate than brittle adhesives for steel structure strengthening by adhesively bonding carbon fibre reinforced polymer (CFRP) due to its greater strain capacity, leading to larger loading and deformation capability. This paper investigated the bond behaviour of CFRP-to-steel joints bonded with a ductile adhesive via numerical studies. Single lap pull tests were also conducted, and the load-displacement relationship at the loaded end and the strain distribution along the CFRP plate were examined. A bond-slip relationship was derived from the test, and based on this, an isosceles trapezoid bond-slip model was proposed. A finite element model was developed for FE analysis of the bond behaviour of the CFRP to steel interface by using the proposed bond-slip model. The finite element model was used to model the experiments, and the good agreement between the experimental results and numerical results demonstrate the effectiveness and accuracy of the finite element model. Finally, a systemically parametric analysis was performed to investigate the effect of FRP modulus, adhesive equivalent strain, adhesive tensile strength and adhesive thickness on initial stiffness, effective bond length and ultimate load. Finally based on the numerical results, a model of effective bond length was proposed.

中文翻译：

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钢与 CFRP 层压板与韧性粘合剂的粘合行为的数值模拟

摘要 韧性胶粘剂比脆性胶粘剂更适合通过胶粘碳纤维增强聚合物（CFRP）来加固钢结构，因为它具有更大的应变能力，导致更大的加载和变形能力。本文通过数值研究研究了用韧性粘合剂粘合的 CFRP 与钢接头的粘合行为。还进行了单圈拉力试验，并检查了加载端的载荷-位移关系和沿 CFRP 板的应变分布。通过试验得出了键滑关系，并在此基础上提出了等腰梯形键滑模型。通过使用所提出的粘结滑移模型，开发了一个有限元模型，用于对 CFRP 与钢界面的粘结行为进行有限元分析。采用有限元模型对实验进行建模，实验结果与数值结果吻合良好，证明了有限元模型的有效性和准确性。最后，进行系统参数分析以研究 FRP 模量、粘合剂等效应变、粘合剂拉伸强度和粘合剂厚度对初始刚度、有效粘合长度和极限载荷的影响。最后基于数值结果，提出了有效键长模型。粘合剂拉伸强度和粘合剂厚度对初始刚度、有效粘合长度和极限载荷的影响。最后基于数值结果，提出了有效键长模型。粘合剂拉伸强度和粘合剂厚度对初始刚度、有效粘合长度和极限载荷的影响。最后基于数值结果，提出了有效键长模型。