Ongoing conflicts worldwide continue to attract high media attention especially with regards to the high numbers of military and civilian casualties being inflicted by mines and improvised explosive devices (IEDs). For the defence sector, the protection of personnel is the highest priority.
While next generation vehicles and equipment will have protective features designed to tackle the threat of IEDs built in, many are still some years away from entering the market. Interim solutions typically involve retro-fitting protective equipment to existing vehicles to minimise cost and speed up delivery to theatre.
The development of such protective features would traditionally involve a great deal of testing and range facilities for blast and require large, remote sites that usually have many usage restrictions and access difficulties. The cost to build prototype vehicles for the sole use of destructive testing also combines to make this approach an expensive and time consuming one.
Computer simulation is therefore a viable alternative to physical testing and offers significant time and cost savings.
The threat of blast pressures on a vehicle consist of several distinct phases. Firstly the initial high incident pressures cause local structural deformation of the outer hull of the vehicle. This in turn can lead to lower limb injuries directly, and other less visible injuries such as hearing damage can be caused by the sudden change in internal pressure. The impulse effect of this high magnitude, short duration loading then leads to acceleration of the entire vehicle. For a blast underneath the vehicle this can lead to spinal compression and lower limb injuries caused during both ascent and as the vehicle lands under its own weight. Another threat is posed by heavy equipment that is carried in lockers and on racking close to the crew and injuries are easily inflicted if these are not properly restrained and/or contained.
Through simulation of the blast pressures on the structure and occupants of the vehicle the threats can be mitigated by adding and optimising energy absorbing material, varying the incident angle of any armour plating (metallic or composite) and designing restraint systems and racking that effectively contain all payload of significant size and mass.
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The HyGe sled facility is a key part of MIRA’s safety offering. It provides safety related testing services to numerous worldwide customers across an ever increasing range of sectors.