Abstract To obtain a good bonding strength of steel/CFRP adhesive joint, the steel surface was machined by grooving process. Short aramid fibers were mixed into the adhesive layer to achieve the further adhesion strength. In the pressing process of steel/CFRP specimen preparation, short aramid fibers with the diameter of several micrometers could be embedded in the grooved gap and the rough surface of CFRP. The higher strength aramid fibers had been not only improved interfacial strength of steel/epoxy and CFRP/epoxy, but also reinforced the adhesive layer due to the bridging activities of aramid fibers. In this study, Mode II fracture strength of grooved-steel/CFRP adhesive joints was investigated by end-notch bending test. The ultimate load and fracture energy of specimens have been improved by 15.7 and 6.8%, in comparison to specimens with smooth steel surface, respectively. The reinforcing mechanisms of CFRP/steel bonding joint as a result of short aramid fibers were discussed according to the failure modes of specimens, and scanning electron microscopy observation and experimental results were carried out.

中文翻译：

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芳纶短纤维增强CFRP/钢复合结构的II型断裂性能

摘要 为了获得良好的钢/CFRP粘接接头的粘接强度，对钢表面进行开槽加工。短芳纶纤维混入粘合剂层以实现进一步的粘合强度。在钢/CFRP试样制备的压制过程中，几微米直径的芳纶短纤维可以嵌入CFRP的凹槽间隙和粗糙表面。较高强度的芳纶纤维不仅提高了钢/环氧树脂和CFRP/环氧树脂的界面强度，而且由于芳纶纤维的桥连活性增强了粘合层。在本研究中，通过端部缺口弯曲试验研究了槽钢/CFRP 粘合接头的 II 型断裂强度。试样的极限载荷和断裂能分别提高了15.7%和6.8%，分别与具有光滑钢表面的试样进行比较。根据试样的破坏模式，讨论了芳纶短纤维对CFRP/钢结合接头的增强机理，并进行了扫描电镜观察和实验结果。