Field test and probabilistic analysis of irregular steel debris casualty risks from a person-borne improvised explosive device

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.

Application of equivalent information method to high reliability assessment of initiating explosive devices

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.

Experimental and numerical investigation on alternatives to sandy gravel

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.

Low Cost,Low Power Magnetic IEDs Detection Method Using Biaxial Magnetometry Digital Sensors

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.

Neural Networks Combined with Importance Sampling Techniques for Reliability Evaluation of Explosive Initiating Device

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.

Blast Injury from Locally Manufactured“Hakka Patas”

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.