Abstract
In this study, the effects of nano-reinforcement on the mechanical response of adhesively bonded single-lap joints with composite adherends subjected to different loading (strain) rates are systematically investigated. The results are then compared to those of the neat thermoset resin and a toughened acrylic–epoxy adhesive. More specifically, nano-reinforced and neat resin-bonded joints mating carbon/epoxy and glass/epoxy adherends were subjected to tensile loadings under 1.5 and 3 mm/min and tensile impacts at a loading rate of 2.04E + 5 mm/min. In some cases, additional tests were conducted to obtain the enhancement in properties that could be gained using the nano-reinforcements for use in our further numerical investigations. The other loading rates tried were 15, 150, and 1500 mm/min. The high loading rate tests were conducted, using a modified instrumented pendulum equipped with a specially designed impact load transfer apparatus. The dispersion of nanoparticles was facilitated using a mechanical stirrer and a three-roll mill machine. The results of the impact tests revealed the positive influence of nano-reinforcements on the loading rate sensitivity of the joints. In all, the overall stiffness and strength of the joints increased as the nano-reinforcement and loading rates were increased. The failure surfaces were then examined with a scanning electron microscope to observe the distribution of the nanoparticles and study the mode of failure.
Acknowledgment
The Natural Science and Engineering Research Council of Canada’s financial support for this research work is gratefully acknowledged and appreciated.