Mechanical properties of shear thickening fluid filled warp-knitted spacer fabrics

This paper reports the compressive behavior and low-velocity impact behavior of warp-knitted spacer fabrics (WKSFs) filled with shear thickening fluid (STF) when subjected to quasi-static compression and low-velocity impact loadings, respectively. In the steady rheological test, the STF experiences a shear thickening transition at a critical shear rate. Besides, the critical shear rate decreases with the increase of silica mass fraction. The compression curves of WKSFs filled with STF composites were consistent with those of WKSFs, including initial, elastic and compaction stage. As the compression speed increases, the overall compression load values of WKSF and WKSFs filled with STF composite increase. Moreover, the compression load of composite increases with the increase of silica mass fraction. Compared with WKSFs, WKSFs filled with STF composite composites need more work to deform under the same strain. The impact result reveals that STF-filled WKSF would absorb more energy and keep the peak load at a lower level than WKSF under the same impact loadings. In a certain range, the energy absorption of composites becomes more excellent with the increasing silica mass fraction. However, over a certain range, the energy absorption of the composite decreases with the increase of the mass fraction of silica. It was concluded that the STF-filled WKSF composite could be expected as a damping or energy-absorptive material for human body protection.