Corner turning and shock desensitization experiments plus numerical modeling of detonation waves in the...

Five new experiments are reported that tested both detonation wave corner turning and shock desensitization properties of the triaminotrinitrobenzene (TATB) based plastic bonded explosive (PBX) LX-17. These experiments used small pentaerythritol tetranitrate (PETN) charges to initiate hemispherical ultrafine TATB (UF TATB) boosters, which then initiated LX-17 hemispherical detonations. The UF TATB boosters were placed under steel shadow plates embedded in the LX-17 cylindrical charges, which were covered by thin aluminum plates. The LX-17 detonation waves propagated outward until they reached the aluminum plates, which were instrumented with photonic Doppler velocimetry probes to measure their axial free surface velocities. X-ray radiographs and framing camera images were taken at various times. The LX-17 detonations propagated around the two corners of the steel shadow plates and into thin LX-17 layers placed between the steel and the top aluminum plates. The detonation waves were met there by weak diverging shocks that propagated through the steel plates and imparted 1-2 GPa pressures to these unreacted LX-17 layers. These weak shock waves compressed and desensitized the unreacted LX-17, resulting in failures of the LX-17 detonation waves. The hydrodynamics of double corner turning and shock desensitization in the five experiments were modeled in two dimensions using the Ignition and Growth LX-17 detonation reactive flow model. The calculated arrival times and axial free surface velocity histories of the top aluminum plates were in excellent agreement with the experimental measurements.