Pore collapse and hot spots in hmx

Author: rcaq

August undefined, 2024

WebJan 5, 2024 · The collapse of pores plays an essential role in the shock initiation of high energy ... simulations to study the formation of hot-spots during the collapse of an 80 nm size void in a ... and J. E. Reaugh, “ Modeling the effects of shock pressure and pore morphology on hot spot mechanisms in HMX,” Propellants Explos. WebJan 17, 2024 · A multi-step thermal-decomposition model is employed to simulate the chemical reaction of the HMX. Firstly, numerical simulations were implemented for a few plane shock experiments and it is demonstrated that the material model of HMX have reasonable accuracy. Then, the pore collapse in a HMX crystal under a shock at 500 m/s …

Pore Collapse and Hot Spots in HMX - Semantic Scholar

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 … WebNov 1, 2024 · Pore collapse thermal-mechanical-chemical responses and underlying physics of (011) and (110) oriented HMX were investigated under the shock velocities of 500 m/s, … ride the ducks seattle crash

Crystal-scale modelling of pore collapse in ... - ScienceDirect

WebJul 20, 2004 · A multiscale modeling strategy is used to quantify factors governing the temperature rise in hot spots formed by pore collapse from supported and unsupported … WebTo 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 ... WebJul 3, 2024 · For temperatures up to 3000 K, the normalized hot spot mass fraction from the cylindrical pore collapse is nearly encompassed by the responses of the realistic pores. The temperature rise and collapse morphology in the elliptical pores, however, show a strong dependence on both pore orientation and aspect ratio. In these simulations, the ... ride the gear train

Phase Contrast X‐Ray Imaging of the Collapse of an Engineered …

Pore collapse and hot spots in HMX - UNT Digital Library

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 details of pore collapse in shock compression experiments, it is useful to study the problem using direct numerical simulation. 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 … ride the eagle movie where to watchWebAug 4, 2004 · An inert material (with the constitutive properties of HMX) is used to better focus on the mechanics of pore collapse. Two important findings result from this study. First, insufficient resolution can significantly overpredict the hot‐spot mass. Second, up to … ride the fenelon place elevator

"WebSep 25, 2014 · Pore collapse and hot spots in HMX. Article. Jul 2004; Ralph Menikoff; Hot spots are critical for initation of explosives because reaction rates are very temperature sensitive. " - Pore collapse and hot spots in hmx

Pore collapse and hot spots in hmx

A study of the pore size effect on the formation of hot spot in a …

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 … WebIn 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.

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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 ... WebNov 1, 2024 · Springer et al. (2024) analyzed the effect of shock pressure and pore morphology on hot spot mechanisms in HMX. Under these high shock strength conditions, ... Pore collapse and hot spots in HMX. AIP Conf. Proc. (2004), pp. 393-396. View in Scopus Google Scholar. Menikoff and Sewell, 2002.

WebJan 28, 2024 · A multiscale modeling strategy is used to quantify factors governing the temperature rise in hot spots formed by pore collapse from supported and unsupported shock waves in the high explosive HMX ... WebApr 13, 2024 · The main reason for friction ignition of HMX-based cast PBX is the friction hot spot generated by microcracks formed after interface damage of the tablet mesoscopic model, ... analyzed and compared four hot spot mechanisms (pore collapse; hole collapse; hole collapse) in the projectile target experiment, shock heating, ...

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. WebNov 1, 2024 · Pore collapse thermal-mechanical-chemical responses and underlying physics of (011) and (110) oriented HMX were investigated under the shock velocities of 500 m/s, 1000 m/s and 2000 m/s. The results provide insights into understanding the hot spot formation and ignition of HEs under shock loading.

Webleads to the formation of hot spots, ... we consider the shock-induced closure of a single pore in -HMX crystal. The problem of pore collapse has been considered in previous work …

WebMay 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 … ride the gap parowan utahWebAug 4, 2004 · Pore Collapse and Hot Spots in HMX. R. Menikoff. Published 4 August 2004. Engineering. Hot spots are critical for initation of explosives because reaction rates are … ride the ferris wheelWebJan 1, 2003 · @article{osti_976649, title = {Pore collapse and hot spots in HMX}, author = {Menikoff, Ralph}, abstractNote = {The computing power now available has led … ride the gods own stallion toWebSep 1, 2024 · A multiscale modeling strategy is used to quantify factors governing the temperature rise in hot spots formed by pore collapse from supported and unsupported … ride the eagle where to watchWeb311j 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 … ride the goodyear blimpWebAug 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 … ride the great divideWebDec 4, 2014 · This paper is devoted to the building of a numerical pore collapse model with “hot-spots” formation for the impacted damage explosives. According to damage mechanical evolution of brittle material, the one-dimensional elastic-viscoplastic collapse model was improved to incorporate the impact damage during the dynamic collapse of … ride the hiawatha bike trail