Experimental investigation of key factors on adhesive properties of skin core for honeycomb sandwich panel with self-adhesive prepreg

Nomex honeycomb and smart self-adhesive prepreg were used to manufacture honeycomb sandwich panels with uniform platen by co-curing process in autoclave. Climbing drum peel test was used to measure their peel strength, and scanning electron microscope was used to observe micromorphology of bonding interface of skin-honeycomb, and the structure of the skin surface after peel and cellular wall ends. Moreover, thickness of cellular wall and composition of impregnated resin were also measured. Combined with the above test results, effects of processing parameters and character of cellular wall ends on the peel strength of honeycomb sandwich panels were studied and types of the adhesive bonding between skin and core were also investigated. It is found that the bond strength increases with the decrease of the temperature ramp rate within a certain range during the co-curing process with uniform platen. However, the pressure-applied moment has no significant effect on bond strength between the skin and core. The honeycomb sandwich panel has higher bond strength when the cellular wall end is rougher or the thickness of the resin layer on the cellular wall is smaller.