Shock-induced detonation of high explosives by high velocity impact

Chen, J. K.; Ching, H. K.; Allahdadi, Firooz A.

doi:10.2140/jomms.2007.2.1701

Cited by 12 publications

(8 citation statements)

References 11 publications

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“…erefore, this model could be used as a theoretical reference for reliable investigations of shock initiations. (3) e critical detonation distances of the noncontact explosion were found to be 25 and 81 mm for a 3 mm thick pressed TNT in the presence and absence of 45# steel-covered plate, respectively. According to the obtained results, increase in the diameter of covered plates containing cylindrical notches increased pressed TNTcritical detonation distance.…”

Section: Discussionmentioning

confidence: 94%

“…Structural properties of covered plates also have significant effects on charge detonation. Taking this into account, researchers have studied the shock initiation of fragments and fragment groups with covered charge structures [3][4][5][6]. Walker and Wasley [7] applied the theory of thermal detonation to study the detonation and impact properties of PBX-9404 and other explosive materials.…”

Section: Introductionmentioning

confidence: 99%

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Investigation of Shock Initiation in Covered Charges under Shock Wave and Fragment Impacts

Chen

Wang

Tang

et al. 2021

Shock and Vibration

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In the current work, a series of step-by-step research methods have been applied to address the damaging effects of near-field strong shock waves and high-speed fragments on covered charge. In the first step, the defects of covered plates due to high-speed fragments were simplified to penetrated notches, and then, these notches were used to evaluate the impact of shock wave loads on charges covered with metal plates. In the next step, we developed a theoretical model to take into account the shock initiation of charges covered with defected metal plates. Explosive initiation standards coupled with shock wave evolution characteristics were applied to specify the crucial conditions of explosive detonation. Finite element program, for instance, was applied for the simulation of shock initiation processes in pressed charges (when TNT was covered with a steel plate containing a penetrated notch), and then, numerical simulations were validated by experimental findings. Finally, the results obtained from the numerical simulations and theoretical model were applied to evaluate the impacts of shock wave intensity, the thickness of covered metal plate, and the geometrical features of penetrated notch on pressed charge shock initiation. The least squares method was applied to determine critical initiation criteria (n and K). Theoretical calculation results were found to be highly consistent with those obtained from numerical simulations, indicating that covered metal plates significantly contributed to charge protection. The results also revealed that notches could undermine the protective function of covered plates and the size and shape of notch significantly affected charge critical detonation distance. Critical detonation distances of noncontact explosions were found to be 25 and 81 mm for a 3 mm thick pressed TNT in the presence and absence of 45# steel-covered plate, respectively. According to the results, increase in the diameter of covered plates containing a cylindrical notch increased pressed TNT critical detonation distance. When dealing with a covered plate containing a normally reflected frustum notch, however, we figured out that any increase in normal reflection slope could decrease pressed TNT critical detonation distance.

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Section: Discussionmentioning

confidence: 94%

Section: Introductionmentioning

confidence: 99%

Investigation of Shock Initiation in Covered Charges under Shock Wave and Fragment Impacts

Chen

Wang

Tang

et al. 2021

Shock and Vibration

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“…Different PBX 9501 lots and different high explosive (HE) thicknesses were reported and compared. Other studies predict much higher threshold impact velocities such as Chen et al [21] with 4 km s −1 which leads to deflagration and detonation for LX-17 explosive.…”

Section: Introduction Motivation and Backgroundmentioning

confidence: 86%

Mesoscale strain and damage sensing in nanocomposite bonded energetic materials under low velocity impact with frictional heating via peridynamics

Talamadupula

Povolny

Prakash

et al. 2020

Modelling Simul. Mater. Sci. Eng.

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The formation of hotspots within polymer bonded explosives can lead to the thermal decomposition and initiation of energetic materials. A frictional heating model is applied at the mesoscale in this study to assess the potential for the formation of hotspots under low velocity impact loadings. The frictional heating mechanism predominantly depends on the formation and growth of microstructural damage within the energetic material. Monitoring of the formation and growth of damage at the mesoscale is considered through the inclusion of piezoresistive carbon nanotube network within the energetic binder providing embedded strain and damage sensing. A coupled multiphysics thermo-electro-mechanical peridynamics framework is developed to perform computational simulations on an energetic material microstructure subject to low velocity impact loads. The coupled framework allows for the assessment of traveling compressive waves caused by impact with piezoresistive sensing, growth of damage with damage sensing and the possible formation of hotspots. The sensing mechanism has been shown to capture the presence of the compressive mechanical wave at different locations within the microstructure before large damage growth. It is observed that the development of hotspots is highly dependent on the impact energy. Higher impact energy leads to larger amounts of microstructural damage providing more damaged surfaces for friction to take place. The higher impact energy also yields larger relative velocities of sliding damage surfaces resulting in more frictional heating. With increase in impact energy, the model also predicts larger amounts of sensing and damage thereby supporting the use of carbon nanotubes to assess damage growth and subsequent formation of hotspots.

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“…The explicit dynamic code AUTODYN is adopted to simulate expansion of the tube and compute a proper core load. AUTODYN is a hydrocode program that is especially suited to solve the interaction problems of different systems of structure, liquid, and gas together, as found in many studies of high explosive simulation [11][12][13][14][15]. To verify the accuracy of the developed model, the numerical results were compared to experimental ballistic test results for different explosive load conditions.…”

Section: Shock and Vibrationmentioning

confidence: 99%

Development of a Numerical Model for an Expanding Tube with Linear Explosive Using AUTODYN

Choi

Lee

Kong

2014

Shock and Vibration

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Pyrotechnic devices have been employed in satellite launch vehicle missions, generally for the separation of structural subsystems such as stage and satellite separation. Expanding tubes are linear explosives enclosed by an oval steel tube and have been widely used for pyrotechnic joint separation systems. A numerical model is proposed for the prediction of the proper load of an expanding tube using a nonlinear dynamic analysis code, AUTODYN 2D and 3D. To compute a proper core load, numerical models of the open-ended steel tube and mild detonating tube encasing a high explosive were developed and compared with experimental results. 2D and 3D computational results showed good correlation with ballistic test results. The model will provide more flexibility in expanding tube design, leading to economic benefits in the overall expanding tube development procedure.

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Shock-induced detonation of high explosives by high velocity impact

Cited by 12 publications

References 11 publications

Investigation of Shock Initiation in Covered Charges under Shock Wave and Fragment Impacts

Investigation of Shock Initiation in Covered Charges under Shock Wave and Fragment Impacts

Mesoscale strain and damage sensing in nanocomposite bonded energetic materials under low velocity impact with frictional heating via peridynamics

Development of a Numerical Model for an Expanding Tube with Linear Explosive Using AUTODYN

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