Investigation on the Synergistic Strain Absorption of <scp>STF/UHMWPE</scp> Angle Interlock Structure Composites With Fluid–Solid Coupling Under Knife‐Stab Behavior

ABSTRACT The angle interlock structure exhibits considerable potential in soft protective materials for multilayer systems. This study combined a shear thickening fluid (STF) with a self‐made ultra‐high molecular weight polyethylene (UHMWPE) angle interlock fabric to create a flexible protective material. Knife stabbing experiments were conducted on composites at different environmental temperatures to investigate the effect of temperature on the stabbing resistance of the composites. A stabbing model of the composite was constructed and analyzed utilizing a finite element simulation (FEM) numerical model alongside Fluid–Solid interaction (FSI) theory, aimed at elucidating the synergistic mechanisms between the angle interlock fabric structure and the STF concerning energy absorption. The findings revealed that the STF enhanced the energy absorption capacity of composites, with improvements ranging from 82.4% to 228.6%. The effect of low temperature on the shear thickening properties was more significant. These results contribute to the further development of new flexible protective composites.