Viscoelastic materials evaluated for blast-resistant designs

Abstract Viscoelastic materials have extensive military applications due to their energy absorption capabilities, with the potential to reduce blast energy imposed on buildings, vehicles, and personnel. Based on current literature, limited information is available regarding the mitigation of blast energy related to these uses. The impact of thickness, nanoparticle addition, and layering variation was assessed in this study using commercially available viscoelastic materials in open-air blasts of Composition C4 to determine shock energy mitigation capabilities. Time-pressure waveforms were recorded to identify optimal changes in shock wave characteristics: reduced peak pressure, positive phase duration, and impulse, with increased rise times. Results were analyzed through trend and linear regression analysis to evaluate factors possibly influencing the behavior of the materials. Polyurethane-based materials reduced peak pressures by extending the positive phase duration, whereas silicone rubber maintained a similar duration with reduced peak pressures, suggesting differing energy dissipation mechanisms. Polyurethane was more effective due to its pressure reduction regardless of thickness, enabling thinner layers to be used to achieve similar results. Overall, thinner layers were more efficient, as diminished returns were evident by asymptotic points once reaching a 7-mm thickness. Incorporating graphene nanoplatelets increased energy transfer with peak pressure increases up to 16% in the polyurethane-based samples and impulse increases of 7.5% in the silicone rubber-based samples, making the baseline samples more effective. Layers alternating in material type reduced peak pressures up to 16% relative to baseline samples, with the most reduction occurring in the thicker layers. The alternate layering patterns proved pivotal in the results, those starting with silicone rubber being correlated to increases of 21% in positive phase duration and 6.5% in decay time.