WebMar 1, 1994 · A spherical pore collapses into an ellipsoid shape giving rise to high temperature regions of hot spots. For micro-pores of diameters below a few hundred … Webhigh hot-spot temperatures, even for a strong shock at the high end of the measured Pop plot. Other dissipative mechanisms applicable to pore collapse are viscous heating and …
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WebJun 27, 2024 · We investigate the effects of shock pressure and pore morphology on the formation and growth of hot spots in HMX (octahydro‐1,3,5,7‐tetranitro‐1,3,5,7‐tetrazocine).
WebMay 7, 2014 · The collapse of microscopic pores contained within a crystal is one such process that localizes energy and generates hot spots. Given the difficulty of resolving the … WebHot spots are critical for initation of explosives because reaction rates are very temperature sensitive. For a plastic-bonded explosive, shock desensitization experiments imply that …
WebJun 27, 2024 · Due to their upstream location in the HMX grain, the surface pores collapse sooner than interior pores; thus, the extent of reaction will generally favor these morphologies because they have more time to grow. In general, multiple smaller hot spots tend to react faster than a single larger hot spot because they accelerate one another's … WebJan 1, 2003 · Here, for the collapse of a single pore driven by a shock, the dependence of the temperature distribution on numerical resolution and dissipative mechanism i s investigated. An inert material (with the constibtive properties of HMX) is used to better focus on the mechanics of pore collapse. ' h o important findings resulted from this study.
WebAug 2, 2024 · This work presents our attempt to examine a single hot spot mode (void collapse) in single-crystal octahydro-l,3,5,7-tetranitro-l,3,5,7-tetrazocine (HMX) embedded in Sylgard. The hot spot heating mechanisms involved with pore collapse include adiabatic heating, jetting, and viscoplastic dissipation. Quantifying the dynamics of a pore collapse ...
Web311j Pore Collapse and Hot Spots in HMX. Approved for public release; distribution i5 unlimited. May 1, 2003. c . Title: MENIKOFF Author(s): RALPH. Submitted to: APS Topical … can fb messenger do group callsWebMay 5, 2024 · It has been widely accepted that the pore collapse is a dominant mechanism of “hot-spot” ignition in pressed solid explosives [[22], [23], [24]], which, in general, includes the viscoplastic deformation, the hydrodynamic micro-jetting, the compression of gas in cavities and the shear bandings, and the explosive maybe enter the process of transition … fit and flare red satin dressWebTo predict the influence of aluminum contents particle size <20 m on the shock initiation and growth of reaction in an aluminized explosive CL-20/AL/Binder, 85/15/5, a new numerical model is utilized. The model is based on the elastic-visco-plastic ... fit and flare rompersWebMay 7, 2024 · @article{osti_1643769, title = {Hotspot formation due to shock-induced pore collapse in 1,3,5,7-tetranitro-1,3,5,7-tetrazoctane (HMX): Role of pore shape and shock … can fda be trustedWebPredictions indicate that hot-spot intensity is only marginally affected by initial porosity ( 1−ϕ⎯⎯⎯s,0 ) for all piston speeds, whereas hot-spot size, number density, volume fraction ... fit and flare print dressesWebIn this study, we explore the effects of high shock pressures (15-38 GPa) with long shock durations and different pore morphologies on hot spot mechanisms in HMX. HMX is chosen as the model material because we have experimental data on many of the chemical-thermal-mechanical properties required for pore collapse simulations. can fda force a recallWebAug 16, 2024 · Small angle neutron scattering (SANS) with contrast variation was used to characterize the fractal behavior and embedded porosity of micro/nano-sized 1,3,5-triamino-2,4,6-trinitrobenzene (TATB) crystallites, gauging the effects of particle sizes on the microstructural features. Scattering results reveal that the external surface of micro-sized … can fbuy life insurance