A theoretical analysis on the perforation of Weldox 460E steel plates struck by flat-nosed projectiles is presented using a previously developed model within a unified framework. This model contains a dimensionless empirical equation to describe the variation of energy absorbed through global deformation as a function of impact velocity. The study further investigates the energy absorption mechanisms of Weldox 460E steel plates, with particular focus on the “plateau” phenomenon, i. e., limited increase in ballistic limit with increasing plate thickness. This phenomenon is explained and compared with results from previously studied 2024-T351 aluminium plates. The model predictions agree well with experimental data for Weldox 460E steel plates impacted by flat-nosed projectiles, including: relationship between global deformation and impact velocity, ballistic limit, residual velocity, and critical conditions for the transition of failure modes. Moreover, the model effectively predicts the “plateau” phenomenon observed in intermediate plate thickness range. It is also found that the indentation absorption energy contributes a significantly larger fraction of the total absorption energy in Weldox 460E steel plates perforated by flat-nosed projectiles than in 2024-T351 aluminium plates, due to the differences in material properties.

Shear thickening fluid (STF) impregnated Kevlar fabric is a new type of composite materials which has better impact resistance as compared with neat Kevlar fabric. On the basis of previous work, a dynamic constitutive model for STF impregnated Kevlar fabric is firstly developed by introducing dynamic increase factor (strain rate effect) and residual strength factor in combination with the rheological properties of STF and yarn pull out test results. Numerical simulations of STF impregnated Kevlar fabric at different impact velocities are then conducted using the proposed constitutive model. Finally, the numerical results are compared with the relevant experimental data. It is shown that the present constitutive model can predict well the impact response of STF impregnated Kevlar fabrics in terms of residual velocity, load-displacement curve and damage morphology, lending support to the accuracy and usefulness of the dynamic constitutive model for STF impregnated Kevlar fabric.