Title:
Explosive Breaching of Reinforced Concrete Walls: Experimental Efforts and Numerical Simulations
Author(s):
Stephen A. Akers, Denis D. Rickman, John Q. Ehrgott, Jr., and Timothy W. Shelton
Publication:
Symposium Paper
Volume:
281
Issue:
Appears on pages(s):
1-14
Keywords:
Zapotec, Microplane, detonation, reinforced concrete, blast, MOUT
DOI:
10.14359/51683623
Date:
12/27/2011
Abstract:
Explosive wall breaching will be a key warfighter capability performed in future military operations by dismounted soldiers in urban terrain environments where the close proximity of urban structures, possibly occupied by non-combatants, significantly restricts the use of large demolition charges or large caliber direct-fire weapons. During the past several years, the U.S. Army has focused considerable attention toward improving methods for breaching walls in the urban combat environment. One major thrust is finding a one-step method to breach the toughest wall that regular Army units are likely to face: an 8-in.-thick, double-steel-reinforced concrete wall. The desired breaching method will produce a totally cleared, man-sized opening through the wall in a single step. Under an Army-sponsored research program, the U.S. Army Engineer Research and Development Center (ERDC) investigated new explosive wall-breaching systems and numerical techniques to model the breaching systems’ interactions with the wall targets. As a first step in this process, ERDC used simple arrangements of Composition C-4 (C4) explosive to conduct a baseline experimental study of breaching effectiveness against reinforced concrete walls.
The primary goal of the numerical effort was to evaluate and validate the predictive capability of both the algorithms in the codes and the constitutive model for the concrete. Numerical simulations of selected experiments were conducted using Zapotec. Zapotec links CTH, a Eulerian shock physics code, and Pronto3D, a transient, solid dynamics Lagrangian code. In these simulations, the concrete and reinforcing steel were modeled as Lagrangian materials, and the C-4 and air were modeled as Eulerian materials. Quasi-static, high-pressure mechanical property tests, e.g., triaxial compression and uniaxial strain, were conducted on the concrete to establish the coefficients for the Microplane constitutive model that was used to simulate the responses of the concrete. This paper presents an overview of results from both the experimental efforts and the numerical simulations.