Powder compaction is one of the most crucial processes in initiating explosive device manufacturing. The quality of powder compaction may influence the performances of product directly. Traditional powder compaction m...Powder compaction is one of the most crucial processes in initiating explosive device manufacturing. The quality of powder compaction may influence the performances of product directly. Traditional powder compaction mainly makes use of manual gravitational spiral loading machine or lever loading machine. Potential accident by the strike in powder compaction of initiating explosive device could risk life, property and the environment. To prevent this risk, automatic control system and control strategy can be used to guarantee no strike in pressing process. The scope of this paper is to analyze and review the control strategy for powder compact and discuss the experimental results for the application of the proposed strategy.展开更多
Person-borne improvised explosive devices(PBIEDs)are often used in terrorist attacks in Western countries.This study aims to predict the trajectories of PBIED fragments and the subsequent safety risks for people expos...Person-borne improvised explosive devices(PBIEDs)are often used in terrorist attacks in Western countries.This study aims to predict the trajectories of PBIED fragments and the subsequent safety risks for people exposed to this hazard.An explosive field test with a typical PBIED composed of a plastic explosive charge and steel nut enhancements was performed to record initial fragment behaviour,including positions,velocity,and trajectory angles.These data were used to predict the full trajectory of PBIED fragments using a probabilistic analysis.In the probabilistic analyses a probability of fatality or serious injury was computed.Based on the results presented,many practical conclusions can be drawn,for instance,regarding safe evacuation distances if a person were exposed to a suspected PBIED.展开更多
The amount of information required for reliability assessment of success/failure products is defined and the formula of equivalent information method is deduced. Based on the formula, a method for assessing reliabilit...The amount of information required for reliability assessment of success/failure products is defined and the formula of equivalent information method is deduced. Based on the formula, a method for assessing reliability of initiating explosive devices with small sample size is established. Compared with the assessment method for devices with large sample size, the new method is correct and feasible and can be used to assess the reliability of initiating explosive devices with high reliability requirements.展开更多
Herein an estimation is given to the efficiency of nuclear explosive devices in a space-rocket complex to withdraw Hazardous Space Objects (HS0)-asteroids and cometary nuclei from the trajectories leading to their d...Herein an estimation is given to the efficiency of nuclear explosive devices in a space-rocket complex to withdraw Hazardous Space Objects (HS0)-asteroids and cometary nuclei from the trajectories leading to their dangerous entry to the atmosphere and falling to the Earth. A conceptual choice of parameters and schemes of application of nuclear explosive devices in impact modules of space-rocket complexes to ensure asteroidal-cometary safety was made.展开更多
The NATO agreement STANAG 4569 defines the protection levels for the occupants of logistic and light armored vehicle.The Allied Engineering Publication,AEP-55,Volume 2 document outlines the test conditions for underbe...The NATO agreement STANAG 4569 defines the protection levels for the occupants of logistic and light armored vehicle.The Allied Engineering Publication,AEP-55,Volume 2 document outlines the test conditions for underbelly improvised explosive device(IEDs),which must be buried in water-saturated sandy gravel.The use of sandy gravel has some drawbacks,for instance reproducibility,time consumption,and cost.This paper focuses on the investigation of four alternatives to sandy gravel,which could produce similar specific and cumulative impulses:a concrete pot filled with water,a concrete pot filled with quartz sand,a steel pot without filling and a concrete pot filled with glass spheres(diameter 200μm—300μm)and different water contents.The impulses are measured with a ring technology developed at the Fraunhofer EMI.A numerical soil model based on the work of Marrs,2014 and Fi serov a,2006 and considering the soil moisture was used to simulate the experiments with glass spheres at different water contents,showing much better agreement with the experiments than the classical Laine&Sandvik model,even for high saturation levels.These results can be used to create new test conditions at original scale that are more cost-effective,more reproducible and simpler to manage in comparison to the current tests carried out with STANAG sandy gravel.展开更多
To test the pulse signal of initiating explosive device (IED) in an aircraft,a multi-channel equivalent system for IED based on Gigabit Ethernet transmission is designed according to its electrical parameters. The out...To test the pulse signal of initiating explosive device (IED) in an aircraft,a multi-channel equivalent system for IED based on Gigabit Ethernet transmission is designed according to its electrical parameters. The output voltage of multi-channel equivalent circuit is converted by analog-to-digital converter (ADC). Then the validity of the converted signal is judged by field programmable gate array (FPGA). Finally,it is transmitted the host computer through Gigabit Ethernet for waveform displaying. Compared with the traditional equivalent equipment of IED,the designed system here can not only test the validity of the pulse signal and normal operation of equivalent circuit,but also realize fast and reliable analysis of pulse signal by means of Gigabit Ethernet. It solves the problems of low speed and lag of response of traditional equivalent equipment.展开更多
The magnetic improvised explosive devices (IEDs), also commonly known as a type of a sticky bomb, is simply constructed devices yet very lethal. This paper puts forward the idea of an electronic compass that is capa...The magnetic improvised explosive devices (IEDs), also commonly known as a type of a sticky bomb, is simply constructed devices yet very lethal. This paper puts forward the idea of an electronic compass that is capable of sensing the change of a magnetic field generated by a magnet and translating it into interpretable data, which could act as the base for the further studies and assist in developing a greener automated system for detecting this device. The electronic compass is specifically chosen for reducing power consumption of systems in addition to the fact that it is available at a low cost.展开更多
Concerning the issue of high-dimensions and low-failure probabilities including implicit and highly nonlinear limit state function, reliability analysis based on the directional importance sampling in combination with...Concerning the issue of high-dimensions and low-failure probabilities including implicit and highly nonlinear limit state function, reliability analysis based on the directional importance sampling in combination with the radial basis function (RBF) neural network is used, and the RBF neural network based on first-order reliability method (FORM) is to approximate the unknown implicit limit state functions and calculate the most probable point (MPP) with iterative algorithm. For good efficiency, based on the ideas that directional sampling reduces dimensionality and importance sampling focuses on the domain contributing to failure probability, the joint probability density function of importance sampling is constructed, and the sampling center is moved to MPP to ensure that more random sample points draw belong to the failure domain and the simulation efficiency is improved. Then the numerical example of initiating explosive devices for rocket booster explosive bolts demonstrates the applicability, versatility and accuracy of the approach compared with other reliability simulation algorithm.展开更多
Explosives are potentially harmful devices that can create an explosion by a rapid release of a pressurized gas consequent to a chemical reaction within the device.They can inflict a variety of injuries,due to the bla...Explosives are potentially harmful devices that can create an explosion by a rapid release of a pressurized gas consequent to a chemical reaction within the device.They can inflict a variety of injuries,due to the blast wave,fire,and shrapnel.The pattern and severity of injuries will be determined by various factors,including explosive potential and constituents such as shrapnel.Homemade explosive devices(HEDs)pose a further threat due to their volatile,unpredictable nature which can lead to accidental explosions.We present the case of a 28-year-old farmer who presented with extensive blast injury to the left hand from a“Hakka patas,”a HED endemic to Sri Lanka.The injuries to his hand consisted of extensive soft tissue and muscle loss,and fractures of metacarpal bones with amputation of the first distal phalanx.Low-grade explosives such as“Hakka patas”have the potential to cause injury greater than expected due to their volatile,unpredictable nature,causing accidental explosions.This can injure unintended targets,resulting in grave consequences.The specific pattern described in low-grade explosive injuries will be important to differentiate other explosive-related injuries for medicolegal purposes.展开更多
文摘Powder compaction is one of the most crucial processes in initiating explosive device manufacturing. The quality of powder compaction may influence the performances of product directly. Traditional powder compaction mainly makes use of manual gravitational spiral loading machine or lever loading machine. Potential accident by the strike in powder compaction of initiating explosive device could risk life, property and the environment. To prevent this risk, automatic control system and control strategy can be used to guarantee no strike in pressing process. The scope of this paper is to analyze and review the control strategy for powder compact and discuss the experimental results for the application of the proposed strategy.
基金This work was supported by the Poland National Center for Research and Development,under the grant DOB-BIO10/01/02/2019 within the Defence and Security Programme.
文摘Person-borne improvised explosive devices(PBIEDs)are often used in terrorist attacks in Western countries.This study aims to predict the trajectories of PBIED fragments and the subsequent safety risks for people exposed to this hazard.An explosive field test with a typical PBIED composed of a plastic explosive charge and steel nut enhancements was performed to record initial fragment behaviour,including positions,velocity,and trajectory angles.These data were used to predict the full trajectory of PBIED fragments using a probabilistic analysis.In the probabilistic analyses a probability of fatality or serious injury was computed.Based on the results presented,many practical conclusions can be drawn,for instance,regarding safe evacuation distances if a person were exposed to a suspected PBIED.
基金Supported by the Ministerial Level Foundation(9140C3705041003)
文摘The amount of information required for reliability assessment of success/failure products is defined and the formula of equivalent information method is deduced. Based on the formula, a method for assessing reliability of initiating explosive devices with small sample size is established. Compared with the assessment method for devices with large sample size, the new method is correct and feasible and can be used to assess the reliability of initiating explosive devices with high reliability requirements.
文摘Herein an estimation is given to the efficiency of nuclear explosive devices in a space-rocket complex to withdraw Hazardous Space Objects (HS0)-asteroids and cometary nuclei from the trajectories leading to their dangerous entry to the atmosphere and falling to the Earth. A conceptual choice of parameters and schemes of application of nuclear explosive devices in impact modules of space-rocket complexes to ensure asteroidal-cometary safety was made.
基金Bundeswehr Technical Center for Weapons and Ammunition WTD-91 GF-440 in Meppen,Germany for funding this work。
文摘The NATO agreement STANAG 4569 defines the protection levels for the occupants of logistic and light armored vehicle.The Allied Engineering Publication,AEP-55,Volume 2 document outlines the test conditions for underbelly improvised explosive device(IEDs),which must be buried in water-saturated sandy gravel.The use of sandy gravel has some drawbacks,for instance reproducibility,time consumption,and cost.This paper focuses on the investigation of four alternatives to sandy gravel,which could produce similar specific and cumulative impulses:a concrete pot filled with water,a concrete pot filled with quartz sand,a steel pot without filling and a concrete pot filled with glass spheres(diameter 200μm—300μm)and different water contents.The impulses are measured with a ring technology developed at the Fraunhofer EMI.A numerical soil model based on the work of Marrs,2014 and Fi serov a,2006 and considering the soil moisture was used to simulate the experiments with glass spheres at different water contents,showing much better agreement with the experiments than the classical Laine&Sandvik model,even for high saturation levels.These results can be used to create new test conditions at original scale that are more cost-effective,more reproducible and simpler to manage in comparison to the current tests carried out with STANAG sandy gravel.
文摘To test the pulse signal of initiating explosive device (IED) in an aircraft,a multi-channel equivalent system for IED based on Gigabit Ethernet transmission is designed according to its electrical parameters. The output voltage of multi-channel equivalent circuit is converted by analog-to-digital converter (ADC). Then the validity of the converted signal is judged by field programmable gate array (FPGA). Finally,it is transmitted the host computer through Gigabit Ethernet for waveform displaying. Compared with the traditional equivalent equipment of IED,the designed system here can not only test the validity of the pulse signal and normal operation of equivalent circuit,but also realize fast and reliable analysis of pulse signal by means of Gigabit Ethernet. It solves the problems of low speed and lag of response of traditional equivalent equipment.
基金supported by the Malaysia Ministry of Higher Education under FRGS Grant No.6071306
文摘The magnetic improvised explosive devices (IEDs), also commonly known as a type of a sticky bomb, is simply constructed devices yet very lethal. This paper puts forward the idea of an electronic compass that is capable of sensing the change of a magnetic field generated by a magnet and translating it into interpretable data, which could act as the base for the further studies and assist in developing a greener automated system for detecting this device. The electronic compass is specifically chosen for reducing power consumption of systems in addition to the fact that it is available at a low cost.
文摘Concerning the issue of high-dimensions and low-failure probabilities including implicit and highly nonlinear limit state function, reliability analysis based on the directional importance sampling in combination with the radial basis function (RBF) neural network is used, and the RBF neural network based on first-order reliability method (FORM) is to approximate the unknown implicit limit state functions and calculate the most probable point (MPP) with iterative algorithm. For good efficiency, based on the ideas that directional sampling reduces dimensionality and importance sampling focuses on the domain contributing to failure probability, the joint probability density function of importance sampling is constructed, and the sampling center is moved to MPP to ensure that more random sample points draw belong to the failure domain and the simulation efficiency is improved. Then the numerical example of initiating explosive devices for rocket booster explosive bolts demonstrates the applicability, versatility and accuracy of the approach compared with other reliability simulation algorithm.
文摘Explosives are potentially harmful devices that can create an explosion by a rapid release of a pressurized gas consequent to a chemical reaction within the device.They can inflict a variety of injuries,due to the blast wave,fire,and shrapnel.The pattern and severity of injuries will be determined by various factors,including explosive potential and constituents such as shrapnel.Homemade explosive devices(HEDs)pose a further threat due to their volatile,unpredictable nature which can lead to accidental explosions.We present the case of a 28-year-old farmer who presented with extensive blast injury to the left hand from a“Hakka patas,”a HED endemic to Sri Lanka.The injuries to his hand consisted of extensive soft tissue and muscle loss,and fractures of metacarpal bones with amputation of the first distal phalanx.Low-grade explosives such as“Hakka patas”have the potential to cause injury greater than expected due to their volatile,unpredictable nature,causing accidental explosions.This can injure unintended targets,resulting in grave consequences.The specific pattern described in low-grade explosive injuries will be important to differentiate other explosive-related injuries for medicolegal purposes.