Numerical Simulations of Explosive Wall Breaching

Explosive wall breaching will be a key war fighter capability in future military operations by dismounted soldiers in urban terrain environments where the close proximity of urban structures, possibly occupied by noncombatants, significantly restricts the use of large demolition charges or large caliber direct-fire weapons. The US Army Engineering Research and Development Center (ERDC) is currently investigating new explosive wall breaching systems and numerical techniques to model the breaching system interaction with the wall targets. The experimental and numerical programs will conduct comprehensive demolition breaching research on a full range of construction and material types and will fully validate new multi-functional breaching procedures across the spectrum of desired missions. As a first step in this process, the ERDC conducted a baseline study of C-4 breaching effectiveness against steel-reinforced concrete walls in FY04. The goal of this effort was to develop improved methods for breaching these walls with simple arrangements of C-4. The experimental breaching scenarios addressed: (1) a baseline study of C-4 breaching, (2) optimal use of C-4 for concrete removal, and (3) optimal use of C-4 for concrete and reinforcing steel removal. Numerical simulations of two selected experiments were conducted using the coupled Eulerian and Lagrangian code Zapotec. In these simulations, the concrete and reinforcing steel were modeled as Lagrangian materials, and the C-4 and air were modeled as Eulerian materials. Two different concrete constitutive models were used in the simulations: the Karagozian and Case concrete model, which is included with Zapotec, and the Microplane model, which was implemented in Zapotec by ERDC personnel. Comparisons between the experimental results and the numerical simulations will be described.