Abstract
The adhesive layer in adhesive bonded joints can be seen as a dense assemblage of tiny adhesive bonding elements. Each element has low load transfer capacity, but its high density arrangement works smooth stress distribution, resulting in effective load transmission and high joint efficiency. In this paper, a type of mechanical joints between CFRP laminates and metal plates consisting of closely arranged ultra-thin pins is proposed. Each pin has only low shear strength, but its dense arrangement achieves high joint strength. Sharp-pointed, small-diameter pins can be pierced through B-staged CFRP laminate without cutting reinforcing fibers and inserted into pre-drilled holes in the metal plate to be joined. Since excess resin fills the gap between the pins and pin holes, the inserted pins are fixedly secured to the inner face of the hole, once the cocuring process is completed. A series of tensile shear tests of the proposed joint under both quasi-static and low-cycle fatigue loading conditions was carried out to investigate the possibility and feasibility of the present method. The tested joints showed both static and fatigue strength comparable to those of the base metal.
