Strain rate dependency on failure load and stress intensity factor of single lap steel joints bonded with epoxy adhesive reinforced with nano-Al2O3 sphere and rod particles

摘要

The failure load of single-lap steel joints (subjected to compressive force) with epoxy/nano-Al2O3 adhesives containing 0.5, 1.0, 1.5, and 2.0 wt% of sphere and rod nano-Al2O3 was analyzed at quasi-static loading. At optimum wt% (1.5 wt%) of nano-Al2O3, the failure load of epoxy/nano-Al2O3 adhesive was determined at high strain rates using Kolsky bar. Critical stress intensity factor of the adhesive layer at the corner of single-lap joints was calculated from the experimentally obtained failure load. A substantial improvement in the failure load and critical stress intensity factor of epoxy/nano-Al2O3 adhesives was achieved compared to the base adhesive at quasi-static and high shear strain rates. Whereas, the failure load of epoxy/nano-Al2O3 adhesives containing 1.5 wt% of sphere and rod nano-Al2O3 at high shear strain rates were 3 to 5 times more than the static failure load of adhesives. The reinforcement of sphere nano-Al2O3 in epoxy had better performance on failure load and critical stress intensity factor of joints compared to rod nano-Al2O3 under the compressive mode of loading.