A constitutive model for shear thickening fluid (STF) impregnated Kevlar fabric subjected to impact loading

Abstract

A constitutive model is presented herein to predict the response and failure of STF impregnated Kevlar fabric under impact loading on the basis of the progressive damage model for fibre reinforced plastic (FRP) laminates. In the constitutive model, the strain rate effect of shear strength is innovatively connected with the rheological property of STF. In order to verify the validity and accuracy of the model, numerical simulations of both ballistic and low-velocity impact experiments of STF impregnated Kevlar fabric are conducted. Furthermore, parametric study is carried out on the influences of impact velocity and rheological behavior of STF. It transpires that the numerical results using the constitutive model are in good agreement with the experimental data in terms of residual velocity, load-displacement curve, energy absorption, global deformation and failure patterns. It also transpires that, with the same impact energy, STF impregnated Kevlar fabric shows stronger resistance to lower velocity ballistic impact. In addition, the maximum viscosity and shear thickening interval of the STF have a significant effect on the ballistic performance of the STF impregnated Kevlar fabric.