Associate professor, Technical University of Nova Scotia, Halifax, Nova Scotia
In real-life applications, adhesively bonded joints that are subjected to in-plane loads will, in turn, experience out-of-plane normal and shear stresses. The resulting stresses, in addition to the brittle nature of most epoxy-based adhesives, often create brittle fracture and failure.
This paper discusses a new approach that was implemented to improve the strength and energy-absorbing capacity of a two-part room-cured epoxy adhesive. Therefore, a comprehensive experimental program was designed to examine the performance and characteristics of aluminum to aluminum and composite-to-aluminum bonded joints. A new test method was used to further verify the increase in ductility and energy-absorbing capacity of the joints. Important issues such as the influence of the interply angle (the lamina orientation angle adjacent to the adhesive), surface preparation, abrasion method, sub-freezing temperature, and the optimum percent inclusion of SiC whisker for improving the strength of the joints were also examined in detail. It was found that the addition of an insignificant amount of SiC whiskers (1% by wt), can significantly improve the shear strength and energy-absorbing capacity of the bonded joint. It was also found that while the application of sub-freezing temperatures reduces the energy absorbing capacity of the bonded joints, a 1% SiC whisker inclusion can completely eliminate such a loss.
Paper ID: CTR10019J