Experimental study of blast wave attenuation using perforated plates and sandwich structures

Blast waves in confined environments generate severe overpressures due to repeated wave reflections, posing significant threats to structures and personnel. Therefore, effective mitigation strategies require experimental evaluation under controlled conditions. In the present study, blast wave attenuation using perforated plates, and hybrid sandwich configurations is investigated experimentally using a shock tube facility. Shock waves with velocities between 500 and 650 m/s were generated using driver pressure ranging from 3 to 12 bar and characterized using high-frequency pressure transducers. Circular and triangular plates with perforation ratios (PR) of 30-50% were examined to assess the influence of perforation geometry and blockage ratio on pressure and velocity attenuation. Results show that blast attenuation increases with blockage ratio and is strongly dependent on perforation shape. Circular perforated plates achieved maximum pressure reduction of approximately 59% at 30% perforation ratio, while triangular perforations resulted in a maximum attenuation of 70% at a perforation ratio of 40%. Among the materials tested, polyurethane foam exhibited the highest attenuation, achieving pressure reductions up to 62% due to its superior energy absorption. Hybrid sandwich configurations combining perforated plates with polyurethane foam further improved blast mitigation, achieving pressure reductions up to 70% along with substantial reductions in transmitted shock velocity.