STF intercalated cork laminates under oblique impact conditions

This study investigates the impact behavior of shear thickening fluid (STF)-intercalated cork laminates under oblique impact conditions. Cork, a sustainable and lightweight material, has gained interest in protective applications due to its energy absorption capabilities. The integration of STF enhances impact resistance by exploiting its shear-thickening properties, providing dynamic stiffening upon loading. The experimental analysis involved drop-weight impact tests conducted at various velocities and angles, evaluating force transmission and energy dissipation. Rheological characterization of the STF confirmed its shear-thickening transition, with a critical shear rate threshold triggering a viscosity surge. The results indicate that STF significantly reduces backface impact forces, with enhanced protection observed at oblique angles exceeding 30°. The interaction between STF and cork structures facilitates improved energy dissipation through adhesive interactions and shear-induced stiffening. Given the recent updates to helmet safety standards such as ECE 22.06 and EN1078, which now include oblique impact testing to address rotational accelerations affecting the brain, the need for advanced protective materials has become more pressing. This study demonstrates the potential of STF-integrated cork composites for advanced protective applications, such as personal protective equipment.