Numerical Assessment Regarding the Influence of the Stiffness of the Material Used to Build Multi-layer Energy-Absorbing Panels on the Absorption of the Shock Wave Energy

Abstract

Mechanical effects of shock waves and waves of relief propagating behind them constitute the main destruction factor of an explosion. The shock wave created as a result of an explosion reaches a destructed object and causes a sudden increase of pressure affecting its surface. The article presents numerical tests regarding the influence of using materials with different stiffness in one of the layers of a multi-layer energy-absorbing panel on the reduction of a load coming from the shock wave affecting the model of a light wheeled armoured vehicle. The assumed aim of the tests was to assess the effectiveness of low-density materials with different stiffness used in a layer of additional external multi-layer energy-absorbing panels. Three systems were selected for the initial analysis of the effectiveness of multi-layer energy-absorbing panels. The effectiveness of absorbing the shock wave energy will be assessed based on the analysis of acceleration characteristics in selected construction points of a vehicle which are the carriers of energy-absorbing panels. In order to tests the effectiveness of energy-absorbing panels, numerical calculations were conducted using the finite element method. The numerical model of the problem was created on the basis of respective physical and mathematical models including a range of physical phenomena and mechanisms which are important in terms of the absorption of the air shock wave energy generated during the detonation of explosives. The CONWEP option implemented in the LS-DYNA system was used to simulate the effects of the shock wave. The effectiveness assessment of the energy-absorbing systems was planned as two-stage tests, i.e. a central explosion carried out on the basis of the test methodology included in AEP-55 vol. 2 and a side explosion carried out in a limited scope of the test methodology described in AEP-55 vol. 3. In those two cases, the effectiveness was assessed on the basis of the result comparison of registered accelerations in vehicle’s characteristic construction points.