The mitigation of primary blast injury: development of energy and weight efficient systems

The literature related to injuries from blast weapons, in both military and terrorist scenarios, indicate the extensive incidence of a range of injuries, from Blast Lung to Bowel and other soft tissue damage. In particular, clinical reports from Israel, indicate the uniqueness and significant mortality from lung and bowel injury from blast. These are often associated with a range of added complications due to infection from widespread tearing of tissues.
The increased incidence of Primary blast injury was the major driver for the formation of CBIS. Progress has been made on the understanding of the limits of the human body with respect to the forces and duration of blast in areas of Blast Lung.
A logical extension is to reduce the incidence of such forms of blast injury in the first instance. This project is to directly address the area of blast mitigation. Reduction of the initial blast insult is obviously and widely reported as a clear method of increasing survivability. However, while many body armour systems function well against ballistic threats, research indicated that such body armour may also increase the risk of injury due to the larger cross section presented to the blast wind.
When faced with the blast and associated kinetic energy a number of factors have to be considered (i) the ability to absorb energy in crumple zones (ii) the ability to redirect that energy (iii) the level of energy that can be safely transmitted with limited injury (iv) the weight, bulk and ease of use of such solutions in the military and civilian spheres.
This project builds on the research initiated by Thuy-Tien Ngoc Nguyen into the reduction of (a) pressure levels (b) impulse delivered and (c) sharpness of loading. This has been investigated using assemblies of perforated plates, varying the open area of the plate and the spacing of the plates. Parallel research has been undertaken to study the effects of granular materials with varying amounts of oils and water present as well as In all cases it was clear that the pressure level and the loading rate can be reduced in a systematic fashion. An exciting area is in the use of functionally graded foam structures which can modify the response according to the loading regime. A basis for producing and studying such systems has been developed within Imperial (ISP and partners).
There is a strong clinical linkage in this project to ensure that the mitigation concepts developed reduce the injury seen by clinicians and are practical for use in field operations. The project will investigate the concepts of blast mitigation both items of clothing, body armour as well as the interiors of vehicles and buildings. The supervisors of this project have significant experience in the fundamental science of mitigation systems and in the clinical environment.