There is an increasing use of improvised explosive devices (IEDs) in terrorist and insurgent activities. Exposure to blast is becoming more frequent. Blast related injuries can be inflicted at various levels. Primary blast injury results from blast wave-induced changes in atmospheric pressure, causing organs and tissues to rupture due to shearing and stretching at different rates. Secondary blast injury results from objects put in motion by the blast wind impacting a person. Tertiary blast injury results from a person being blown into solid objects by the blast wind. This paper deals with the protection system against primary blast injury by mitigating blast wave.Shear and stress waves from the primary blast could potentially cause traumatic brain injury (TBI) directly. Very often no external physical injuries are detected in the affected victims, but serious damages are inflicted internally, particualarly to the brain where neurological effcts can be slow to appear. In this work, we explore the use of metacomposites to build a protection system that can mitigate dynamic loads and attenuate blast wave. Firstly, the concept of elastic metamaterials is introduced by presenting the unique property of negative effective mass density through simple analytical mass-in-mass models. Next, the impact wave annenuation and blast wave mitigation capability of the metacomposites are demonstrated using computational simulation. Finally, practical ways to design and manufacture metacomposites protection system with negative effective mass density are proposed and presented.
Available at: http://works.bepress.com/kwek_tze_tan/19/