Analysis of a light caterpillar vehicle loaded with blast wave from detonated IED

More and more impudent attacks on the military convoys in Afghanistan proved a huge danger of the improvised explosive devices - IED. Huger and more clever charges are a serious problem for vehicles protection. Additionally, hitherto defence standards and STANAG didn't predict such huge charges. Majority investigations were based on a 3 kg anti-tank mine. The article presents the results of numerical calculations for the elements of the combat vehicle supporting structure loaded with an impact generated by explosion of a huge explosive charge under the bottom of the vehicle with consideration of the wave reflected from the ground. Such an approach allows obtaining a good approximation of numerical simulations to real conditions of terroristic attacks. Additionally, the analysis of IED side influence on the vehicle shell was conducted. The explosive charge — IED — was simulated with the use of concentrated energy of properly selected (on the base of literature investigations) density and initial energy. During analyses of side explosive on the vehicle structure, the obstacle in the form of a building increasing the pressure impulse was taken into account. The paper presents the results of a numerical analysis in which Euler and Lagrange domains(describing a vehicle) were coupled. A perfect gas model was used to describe air parameters.. Additionally, the ground was described with a gas model. Every kind of material data were selected on the base of experimental investigations. A bilinear material model with a Cowper and Symonds strain rate model was used to describe a vehicle. Such an approach fully describes the phenomena occurring in the system.