Investigation of high-strain rate behavior of shear thickening fluid encapsulated electrospun ultra-high molecular weight polyethylene/high-density polyethylene fiber composites by split-Hopkinson pressure bar

This study examines the high-strain rate behavior of shear thickening fluid (STF)-encapsulated samples of an electrospun mat. It comprises sandwich layers of STF-impregnated ultra-high molecular weight polyethylene (UHMWPE)/high-density polyethylene (HDPE) mat enclosed within high-temperature stretched electrospun neat UHMWPE fabric. The UHMWPE/HDPE mat was chosen for STF impregnation due to its porosity and the texture of its fiber surface, which contains pores, pits, wrinkles, and grooves ranging in size from nano- to micron-scale. This feature enhances the adhesion and absorption of STF into the fiber structure and onto the fiber surface. These STF-contained and corresponding neat samples were tested using an in-house-designed split-Hopkinson pressure bar. The deformation and fracture behavior of samples were also monitored simultaneously using a high-speed camera. The results showed that at a higher strain rate, the peak stress and energy absorption of STF-encapsulated samples were more elevated due to increased inter-fiber friction, unlike neat samples, which show a declining trend in peak stress and energy absorption due to yarn slippage. Moreover, the deformation during impact in neat samples was higher than in the STF-encapsulated samples.