Post-blast explosive residue : a review of formation and dispersion theories and experimental research

The presence of undetonated explosive residues following high order detonations is not uncommon, however the mechanism of their formation, or survival, is unknown. The existence of these residues impacts on various scenarios, for example their detection at a bomb scene allows for the identification of the explosive charge used, whilst their persistence during industrial explosions can affect the safety and environmental remediation efforts at these sites. This review article outlines the theoretical constructs regarding the formation of explosive residues during detonation and their subsequent dispersal and deposition in the surrounding media. This includes the chemical and physical aspects of detonation and how they could allow for undetonated particles to remain. The experimental and computational research conducted to date is discussed and compared to the theory in order to provide a holistic review of the phenomeno

Guideline - Building Perimeter Protection: Design Recommendations for Enhanced Security against Terrorist Attacks

The purpose of the current document is to provide guidance to security and law enforcement officials, building/site owners, venue organizers, state organizations, engineers and other stakeholders that are in charge of securing facilities and critical infrastructures against the growing international terrorist threat. The focus of the report narrows down into recommendations for a robust and usable approach for the physical protection of infrastructures against this borderless phenomenon. It addresses shortcomings encountered in the design of such security solutions and aims at producing a simple, self-contained practical guide to enable the selections and installation of elements that are able to stop and/or deter potential terrorist attacks. A detailed analytical procedure is illustrated for identifying the weaknesses of potential terrorist targets and assess the relevant risk for different terrorist tactics. Advice is provided for the introduction of protection measures against both external and internal explosions and design methodologies are presented for minimizing the likelihood for the development of a progressive collapse mechanism. Moreover, specialized perimeter physical protection measures are proposed that may successfully restrict unauthorized vehicle and intruder access, supplemented by the employment of modern digital technologies, such as video surveillance, smart sensors and video analytics. The novel and emerging threat landscape is also addressed, such as the malicious use of Unmanned Aircraft Systems, requiring new response strategies that call for the adoption of state-of-the-art counter technologies.JRC.E.4-Safety and Security of Building

Creating and Operating the Nuclear Urban Kinetics Effects Simulator

The ability to create an accurate method for determining the composition of post-detonation debris in an urban environment is an essential component of a proper nuclear forensics program. The methods necessary to create a high fidelity computer for modeling urban debris matrix creation is addressed. These methods include detonations varying in location in the lower 48 continental states and the yield of the weapon. The ultimate goal of the research conducted in this area is to provide the nuclear forensics community with an effects modeling code that generates accurate urban surrogate recipes to be analyzed in laboratories. This code can be scaled to incorporate other blast scenarios that alter the final matrix composition

Detecting Violent Explosive Neurologic Trauma in American Service Members

The emergence of high explosives on the battlefield can be defined both literally and figuratively as a seismic event in the landscape of modern warfare. High explosives first came into common use in war in 1914. By the end of World War I just four years later, more than 2.5 billion tons artillery and mortar shells had been detonated. Many veterans were repatriated home physically unscathed but were nonetheless left with an assortment of inexplicable psychological and cognitive complications. Originally referred to as “shell shock”, Post-Traumatic Stress Disorder (PTSD) is the current nomenclature used to explain the myriad of psychological complications arising from combat exposure. Recent studies have shown that these symptoms may be more physiological than they are psychological. Proximal exposure to explosive atmospheric overpressure waves have been shown to cause astroglial scarring in vital regions of the brain often associated with symptoms of PTSD. With the highest ratio of American casualties from explosives since WWI, violent explosive neurologic trauma has once again emerged as the signature injury of an armed conflict in the Global War on Terrorism. Modern preliminary diagnostic protocols have insufficient specificity to accurately distinguish patients exposed to blast shockwaves with traumatic brain injury versus those solely with psychological trauma. Consequently, tens of thousands of American veterans have received misdiagnosis or insufficient treatment of permanent post-concussive syndrome following explosive blast wave exposure. Key Words: traumatic brain injury, diffuse axonal injury, primary blast injury, explosive neurologic trauma, Global War on Terrorism, counterinsurgency, post-traumatic stress disorder, post-concussion syndrom

Adequacy of test standards in evaluating blast overpressure (BOP) protection for the torso

The blast wave emanating from an explosion produces an almost instantaneous rise in pressure which can then cause Blast Overpressure (BOP) injuries to nearby persons. BOP injury criteria are specified in test standards to relate BOP measurements in a testing environment to a risk of BOP injury. This study considered the adequacy of test standards in evaluating BOP protection concepts for the torso. Four potential BOP injury scenarios were studied to determine the likelihood of injury and the adequacy of test standards for appropriate protection concepts. In the case of vehicle blast, BOP injury is unlikely and test standards are adequate. In the scenario involving an explosive charge detonated within a vehicle, and the close proximity to a hand grenade scenario, test standards are not available. The demining scenario was identified as of importance as test standards are available, but do not mandate the evaluation of BOP protection. A prototype South African Torso Surrogate (SATS) was developed to explore this scenario further. The SATS was required to be relatively inexpensive and robust. The SATS was cast from silicone (selected to represent body tissue characteristics) using a torso mould containing a steel frame and instrumented with chest face-on pressure transducer and accelerometer. The SATS was subjected to an Anti-Personnel (AP) mine test and the Chest Wall Velocity Predictor and Viscous Criterion were used to predict that BOP injuries would occur in a typical demining scenario. This result was confirmed by applying the injury criteria to empirical blast predictions from the Blast Effects Calculator Version 4 (BECV4). Although limitations exist in the ability of injury criteria and measurement methods to accurately predict BOP injuries, generally a conservative approach should be taken. Thus, it is recommended that the risk of BOP injuries should be evaluated in demining personal protective equipment test standards

Understanding the Humanitarian Consequences and Risks of Nuclear Weapons : New findings from recent scholarship

Publisher PD

Study of blast effects on structures

Engineers have a duty to the public to preserve life and protect the community and occupants within structure that we build and use. All practicing engineers are obligated to foster the health, safety and wellbeing of the community and the environment. This involves acting on the basis of adequate knowledge and foreseeable risks that pose a potential hazard towards the built environment. The terrorism threat has evolved rapidly in scale and occurrences in recent history and with that the need to create resilient structures. This dissertation endeavours to undertake a study of the global blast loading effects on structures and identify techniques for improved structural resilience of critical elements. Blasts can be delivered by explosive events either deliberate, accidental or through indirect action. A historical review of case studies and blast incidents was undertaken to identify susceptible structures to blast and development of a structural model in order to simulate a credible scenario and understand the blast effects and predicting the design loading. The scope of the dissertation is restricted to the blast pressure disturbance effects interacting with a structure delivered by an external air blast and not considering the secondary effects of a blast incident including thermal and high velocity fragments. Common structural members and materials were used to devise a Finite Element model and simulate against the blast loading cases derived from empirical methods. Since the nature of blast load only lasting for a short time and undergoes constant change Non-Linear Transient Dynamic Analysis approach was well suited to undertaking this type of analysis. Some of the findings include whipping effects due to inertia as the structure accelerating from its initial position to develop resistance against the applied loading even after the applied load has ceased. The global response of a structure due to blast pressure, is generally a consequence of lateral or out-of-plane loading. Longer pressure phase durations tend to result in bending failures while impulsive loads (short pressure phase duration) lead to shear responses. Resilience techniques including steel UC encased in concrete, RC steel plate wraps and RC shear reinforcement lacing have the potential to improve the robustness of structural elements reducing overall displacements and stress responses

Army Officer Corps Science, Technology, Engineering and Mathematics (STEM) Foundation Gaps Place Countering Weapons of Mass Destruction (CWMD) Operations at Risk – Part 1

This is the first of three articles from the authors describing the risk to Joint Operations incurred by an Army that is vulnerable to the STEM challenges faced in a great power competition involving CWMD operations. In this article, we describe the problem. In articles two and three of the series, we will elaborate on the problem utilizing the Joint Publication 3-0 as our guide and recommend solutions to address this gap

Air Force Institute of Technology Research Report 2010

This report summarizes the research activities of the Air Force Institute of Technology’s Graduate School of Engineering and Management. It describes research interests and faculty expertise; lists student theses/dissertations; identifies research sponsors and contributions; and outlines the procedures for contacting the school. Included in the report are: faculty publications, conference presentations, consultations, and funded research projects. Research was conducted in the areas of Aeronautical and Astronautical Engineering, Electrical Engineering and Electro-Optics, Computer Engineering and Computer Science, Systems and Engineering Management, Operational Sciences, Mathematics, Statistics and Engineering Physic