ABSTRACT
A novel film adhesive was proposed to bond carbon fiber reinforced polymer (CFRP) laminas to steel substrates to improve comprehensive bonding performances in terms of bond strength, toughness and high-temperature behavior. This film adhesive was shown to possess excellent high-temperature resistance via dynamic mechanical analysis (DMA). CFRP-steel double-lap joints (DLJs) were experimentally studied at room and elevated temperatures, focusing on the failure modes, effective bond length, bond-slip relationship, and bond strength. The results show that the film-adhesive bonded joints failed with CFRP delamination. The bonding interface has an effective bond length of approximately 65 mm, beyond which no increase of ultimate load can be achieved with the increase of bond length. The bond-slip relationship of the film-adhesive bonding interface exhibits a trapezoidal (ductile) shape at room temperature (25℃), which transfers to bilinear or bilinear-like shapes at elevated temperatures. It is also found that the joint bond strength can retain 96% at 70℃ compared with that at 25℃. In all, bonding interfaces with superior strength, ductility, and high-temperature resistance in CFRP-steel composites are achieved by using the new film adhesive.
