Assessment of Fatigue Crack Growth in Aluminum Bonded With a Nanoparticle Reinforced Composite Patch

ABSTRACT Adhesively bonded patch repairs tend to exhibit an effective bond around the crack, making them efficient for retarding the crack growth rate. The present research examines the effect of adding nano‐boron carbide (B ₄ C) particles to carbon fiber‐reinforced epoxy patch material used to retard the fatigue crack propagation (FCG) in 6061‐T6 aluminum alloy. In this context, the B ₄ C particles are included in different weight percentages (wt.%): 0, 0.2, 0.4, and 0.6. The compact tension (CT) specimens are pre‐cracked to a depth of 1 mm with a maximum load of 1 kN at load ratios of 0.1 and 0.3. Then, the pre‐cracked specimens are patched using composite patches infused with varying wt.% of B ₄ C nanoparticles. A significant reduction in the stress intensity factor (SIF) and fatigue crack growth rate is observed with increasing wt.% of B ₄ C nanoparticles. Eventually, 0.6 wt.% B ₄ C inclusion outperformed by increasing the fatigue life of the cracked aluminum specimen by 4.5‐fold, compared to the unpatched sample.