Combined Blast & Fragment Test for Textiles: Effect of the stochastic response of electrical detonators on the time interval between consecutive loads

Protective textiles for military applications must withstand both fragment and blast impacts. However, current testing
protocols solely assess ballistic resistance, overlooking the complex dynamic interactions between blast waves and high
velocity fragments. This results in an inadequate evaluation of protective performance for real-world explosive scenarios. To
address this, an experimental setup capable of generating a synchronized planar blast wave and high velocity fragment is used
to evaluate the explosion resistance of various textile solutions. A key challenge of the setup lies in precisely controlling the
time interval between blast and fragment impacts, as the resistance of the textiles varies depending on the impact phase. At
critical time intervals, textiles exhibit reduced impact resistance. The primary source of uncertainty in this timing control stems
from variability in the detonator's response time after receiving the initiation signal. To quantify and refine control over this
delay, two electrical circuits are designed: one employing a voltage divider to measure the response time and one integrating a
custom-made shunt to monitor the current flowing through the detonator prior to detonation. Tests are conducted under various
laboratory power supply conditions (20V/2.5A, 30V/2.5A, 60V/2.5A) and utilizing a blast machine to characterize the
detonator’s response across different operating configurations. By accurately characterizing the detonator’s initiation
parameters, including timing precision and energy input, a predictive rough estimation of the detonation time delay can be
developed in function of the voltage input. The results will guide the development of the next generation of protective textiles.