A frictional work predictive method for the initiation of solid high explosives from low-pressure impacts

The goal of these tests was to provide information that would aid in the prediction of HE response in accident situations where the initiating stimulus was less than that required for direct shock initiation. Before these tests were run, a prediction of threshold impact velocity was made (70m/s) using a rough average of previously reported threshold factional work from skid tests (1 cal/cm{sub 2}) and the experimental value for coefficient of friction of 0.5({plus_minus}) measured in the same tests for PBX-9404. The actual testing proved the threshold impact velocity to be much less, and the pretest prediction was not only wrong, it was not conservative. This work presents a methodology for more accurately predicting the reaction threshold for HE involved in an accident such as an airplane crash or a severe land transportation accident. The main focus of this work is on LX-10-1 (94.5% 5.5% Viton A binder, density 1.86g/cm{sup 3}). Additional work was done on LX-17 (92.5% TATB, 7.5% KelF binder, density 1.90g/cm{sub 3}), a very insensitive explosive. The explicit two-dimensional finite element code, DYNA2D, was used to model the tests and predict the HE response. The finite element mesh of the projectile and target were generated using MAZE.more » The post-processing of the DYNA2D analysis was done with ORION.« less