Effect of the tin- versus air-side plate-glass orientation on the impact response and penetration resistance of a laminated transparent armour structure

Our recently developed continuum-level, physically based, high strain-rate, large-strain, high-pressure mechanical material model for soda-lime glass has been enhanced to include differences in the flaw-size population between the so-called air-side and the so called tin-side of float-glass plates, and adapted for use in the case of borosilicate glass. The model was structured in such a way that it is suitable for direct incorporation, as a material user-subroutine, into standard commercial transient non-linear dynamics finite-element-based software packages. The model was parameterized using various open-literature sources. The experimental portion of the work, which consisted of 28 projectile impacts onto glass/polyurethane/polycarbonate-based test laminates, was intended to allow for quantification of the effect of air-versus tin-side borofloat strike surface when incorporated into a multi-layer, multi-functional test laminate. Experimental findings indicated the lack of a significant difference in the impact resistance of air-versus tin-side test laminate strike surfaces. Subsequent to these findings, computational simulations were carried out in order to establish if the proposed borofloat material model could capture the prominent experimentally observed damage modes and the measured V50, reconfirming the experimental findings. In general, a good agreement was found between the computational and the experimental results.