Visualization and Mechanical Response of Damage Mechanisms in HMX Based Energetic Composites
Abstract
Hotspot (localized heating) in energetic composites can result in unintended ignition of the material. Due to the necessary safety concerns involved with this type of failure of polymer-bonded explosives (PBX), understanding the mechanical mechanisms that form hotspots is important. These mechanisms are well studied and observed at low strain rates. At high strain rates, however, visualization is difficult due to the opaque nature of the materials. By combining x-ray phase contrast imaging with Kolsky bar dynamic compressive and dynamic tensile experimentation, PBXs consisting of octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX) crystals and either hydroxyl-terminated polybutadiene (HTPB) or Sylgard 184 binder were successfully visualized in-situ at high-speed. The mechanical mechanisms of cracking in the HMX crystals and debonding between the crystal and binder, which may lead to hotspot formation, were observed and analyzed.
Degree
M.S.A.A.
Advisors
Chen, Purdue University.
Subject Area
Aerospace engineering|Mechanical engineering|Materials science
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