Aminated carbon nanotube enhanced composite T-joints mediating CFRP load-bearing capacity improvement

Adhesive bond is the weakest part of carbon fiber reinforced composites (CFRP) force-bearing structure. Therefore, enhancing the strength of the adhesive bond is key to improve force-bearing structure. In this study, adhesive strength of the common CFRP T-joint was enhanced by aminated carbon nanotubes (CNT). To begin with, shear tensile strength of single-lap-joint laminated composites with various CNT content was verified, which peaked at 0.5 wt%. It was indicated that the adhesive bond of deltoid is the weakest area in a T-joint. CNT was applied in the deltoid of composite T-joint and pull-off test was conducted to investigate the progress from the initiation and evolution of damage as well as the final failure. The aminated CNT employed in this study formed an effective load transmission through physical engagement and chemical bonding; the addition of 0.5 wt% CNT effectively enhanced tensile strength and toughness, improving mechanical property of the adhesive bond. This study provides a solution to enhance the adhesive area of CFRP load-bearing structure with CNT, consequently improve the load-bearing strength of composite.