Field tests and computational simulations of the explosion of buried charges

¹ DGA Techniques terrestres, Rocade Est, Echangeur de Guerry, 18000 Bourges Cedex, France
² Laboratoire 3SR, Domaine Universitaire, BP. 53, 38041 Grenoble Cedex 9, France

^a Corresponding author: eve.roger@intradef.gouv.fr

Published online: 7 September 2015

Abstract

Modelling buried explosion is a matter of concern for vehicle protection. Indeed, in the battlefield, Improvised Explosive Devices (IEDs) are one of the major threats for land vehicles and, more specifically, for their underbelly. Two series of field tests using several masses of explosives have been performed, varying certain geometrical parameters, the nature and the physical properties of the soil. These controlled tests have shown that the impulse transmitted to the vehicle is a function of the saturation of the soil as well as of depth of burial of the explosive. In an effort to simulate the phenomena that take place during the explosions, these tests have been used to feed the data requested in computational simulations in a finite element context. Soil modelling presents its own difficulties, especially because soil is a porous medium and the three phases (solid grains, water and air) must be considered. A non linear viscoplastic cap model has been developed where the degree of saturation is variable. The yield surface includes a failure part, a cap and a tension cutoff. Soil stiffening associated with the air expulsion has been observed to be an important aspect of the model.