Improvised Explosive Device Attacks Research Articles

Space–Time Modeling of Insurgency and Counterinsurgency in Iraq

The US and its Coalition partners concluded combat operations in Iraq in August 2010. Rather surprisingly, little empirical evidence exists as to the factors that contributed to the ebb and flow in levels of violence and the emergence and disappearance of hot spots of hostilities during the campaign. Building upon a tradition of criminology scholarship, recent work demonstrates that Improvised Explosive Device (IED) attacks are clustered in space and time and that these trends decay in a manner similar to that observed in the spread of disease and crime. The current study extends this work by addressing a key potential correlate of these observed patterns across Iraq—namely, the timing and location of a variety of Coalition counterinsurgency (COIN) operations. This is achieved by assessing the co-evolving space–time distributions of insurgency and counterinsurgency in the first 6 months of 2005. To do so, we employ a novel analytic technique that helps us to assess the sequential relationship between these two event types. Our analyses suggest that the number of COIN operations that follow insurgent IED attacks (moderately) exceeds expectation (assuming that events are independent) for localities in the vicinity of an attack. This pattern is more consistent than is observed for the relationship in the opposite direction. The findings also suggest that less discriminatory COIN operations are associated with an elevated occurrence of subsequent insurgency in the vicinity of COIN operations in the medium to long term, whilst for more discriminatory and capacity-reducing COIN operations the reverse appears to be true.

Airport front-of-house vulnerabilities and mitigation options

A method for risk-informed comparison of mitigation options in situations with large epistemological uncertainties is presented by example: that of an improvised explosive device (IED) attack at a generic airport front-of-house (FoH). Specifically, a probabilistic model is built and distributions of scaled fatalities from probabilistic combinations of vehicle-based IED and personnel-based IED threats are generated using Monte Carlo methods. A risk assessment of the threats is given from the statistics of the scaled fatality distributions. We consider the risk reduction due to a combination of mitigation options, including IED screening, vehicle stand-off, and interception and detection. Sensitivity and stress analysis show that the ranking of the options, by their risk reduction, is relatively robust to the epistemological uncertainty incorporated into the model. The qualified conclusion of the example is that vehicle stand-off is the priority risk-effective mitigation option for IED attack at a generic FoH.

Fractures of the Thoracolumbar Spine Sustained by Soldiers in Vehicles Attacked by Improvised Explosive Devices

Retrospective analysis. To analyze the types of orthopedic spine fractures sustained by North Atlantic Treaty Organization soldiers when vehicles are attacked by improvised explosive devices (IEDs), with specific focus on the flexion-distraction type thoracolumbar fracture (Chance fracture). Operation Enduring Freedom is the North Atlantic Treaty Organization's effort in Afghanistan. IED attacks on armored vehicles are common and account for high proportion of soldiers' deaths and injuries. Retrospective record review was accomplished on soldiers admitted to a military hospital with orthopedic spine fractures after IED attacks on vehicles from January 1, 2008 to May 15, 2008. Thoracolumbar fractures were classified using the McAfee classification system. Twelve male patients with 16 thoracolumbar fractures were identified (3 patients with multiple fractures). The 16 thoracolumbar fractures included 6 flexion-distraction fractures in 5 patients (38%, 6/16: two T12, two L1, one L3, and one L4), 7 compression fractures in 5 patients (44%, 5/16; one T7, one T8, two L1, one L2, one L3, and one L4), and 3 burst fractures (19%, 3/16; two L1 and one L2). The incidence of flexion-distraction thoracolumbar (Chance) fractures has been reported to be between 1.0% and 2.5% in most spine fracture series. In this small study, Chance fractures represented 38% of all tho-racolumbar fractures sustained after IED attack on armored vehicles. The blast pattern associated with IED explosion may be responsible for the high rate of these injuries in vehicle occupants.

Mitigation of blast effects on aluminum foam protected masonry walls

Terrorist attacks using improvised explosive devices (IED) can result in unreinforced masonry (URM) wall collapse. Protecting URM wall from IED attack is very complicated. An effective solution to mitigate blast effects on URM wall is to retrofit URM walls with metallic foam sheets to absorb blast energy. However, mitigation of blast effects on metallic foam protected URM walls is currently in their infancy in the world. In this paper, numerical models are used to simulate the performance of aluminum foam protected URM walls subjected to blast loads. A distinctive model, in which mortar and brick units of masonry are discritized individually, is used to model the performance of masonry and the contact between the masonry and steel face-sheet of aluminum foam is modelled using the interface element model. The aluminum foam is modelled by a nonlinear elastoplastic material model. The material models for masonry, aluminum foam and interface are then coded into a finite element program LS-DYNA3D to perform the numerical calculations of response and damage of aluminum foam protected URM walls under airblast loads. Discussion is made on the effectiveness of the aluminum foam protected system for URM wall against blast loads.