Grammar of Impact Sensitivity: An Incremental Theory

In this paper, we report the first attempt to quantify
impact sensitivity
using the second-order incremental approach based on the structural
features of explosives. It has been found that impact height (h50) can be expressed via a multiplicative incremental
exponential form, in which the exponents are characteristic coefficients
of structural increments multiplied by their numbers in the molecule.
The method was developed on a large array of experimental data (450
molecules and salts) of different energetic materials, namely, nitro
compounds, peroxides, nitrogen-rich salts, heterocycles, etc., while
testing of the model was performed for 170 compounds. The results
demonstrate a noticeable correlation with the experimental h50 values. Thus, the corresponding R2 and RMSE for the training and test sets are 0.56 (12.5
J) and 0.63 (18.8 J), respectively. In this work, we use 53 individual
structural increments, but their number can be extended, and the corresponding
coefficients can be refined; this allows for increasing the prediction
accuracy on-the-fly. The calculation algorithm is discussed, and the
corresponding examples are presented. The performed machine-based
regression analysis using genetic function approximation, multiple
linear regression, and artificial neural network has proven the reasonability
and informativity of the proposed incremental theory. Thus, the developed
approach significantly extends our understanding of the impact sensitivity
phenomenon and translates it into the category of one that can be
calculated by a pocket calculator.