Effect of boundary dimension on energy absorption behaviour of shear thickening fluids under impact

Abstract

This study examined the effect of boundary dimension on the energy absorption behaviour of concentrated shear thickening fluids (STFs). STFs were filled into a steel container with various depths and diameters and were impacted by a cylindrical striker. It was found that the energy absorption behaviour showed a response time after which an effective impact-resistant performance was demonstrated. Then, a simplified two-dimensional model was proposed to clarify the characteristics and mechanism of energy absorption behaviour of the impacted STF. For a relatively shallow STF, the energy absorption is mainly achieved by the axial compression of a semi-ellipsoid like jamming region underneath the striker with less radial boundary confinement. Therefore, an increase in depth weakens the energy absorption performance because of the delayed response time for the effective energy absorption. By comparison, the increase in diameter causes the reduction of interaction between the jamming region and the surrounding liquid-STF, slightly degrading the energy absorption performance. For a deep STF, this jamming region reaches to the lateral boundary prior to the effective energy absorption which is primarily achieved by both the compression and bending of the jamming layer supported by the underneath liquid-STF. Thus, an increase in diameter leads to a decrease in the energy absorption performance.