O-029 A New Approach to Assessment and Design of Insensitive Munitions by Analysis of Critical Mechanisms that may be Initiated by Unplanned Stimuli

September 1996
Andrew J. Sanderson (Energetic Materials) , Emmanuel Thivillier (ENSIETA, Brest, France)

It is not possible to comprehensively model the tests used in insensitive munitions (IM) assessment. Neither is it possible to directly correlate small scale (laboratory) tests to the all-up-round (AUR) IM tests. Yet AUR IM tests are extremely expensive and by themselves they give little or no reliable information about the real vulnerability of the round under test. Therefore it is of prime importance that if possible, modelling and laboratory tests are used to increase confidence in IM assessment or ideally to reduce the amount of AUR testing needed.

This paper discusses the present IM assessment method and proposes an improved alternative method that makes maximum use of currently available modelling and laboratory testing technology. This method is based on an initial threat hazard assessment followed by an analysis of the Critical Reaction initiation and growth mchanisms (CRIMES) that may ensue. The CRIMES being known, the tests, modelling and analysis necessary to determine the response of the AUR to the threats are identified. The severity of the response is then determined from modelling and small scale tests, and the results are given as probabilities of severity of each possible response (on a continuum from no reaction to detonation). This analysis method uses no AUR testing and the assessment of the AUR to each IM threat can be related to a vulnerability requirement or specification.

The advantages of this approach include:

  • prior knowledge of exactly what data will be needed for the assessment of a munition from the design stage;
  • greatly increased confidence in the final munition vulnerability assessment;
  • cheaper IM assessment;
  • knowledge of the reliability of the results;
  • the possibility of stating simple IM requirements that allow for the complexities of reality.