Thesis (M.S.)--Naval Postgraduate School, 2004. / Title from title screen (viewed Nov. 10, 2004). "March 2004." Includes bibliographical references (p. 65-69).

Thesis (M.S. in Joint Campaign Planning and Strategy)--Joint Forces Staff College, Joint Advanced Warfighting School, 2005. / "24 May 05." Electronic version of original print document. Includes bibliographical references (p. 64-69).

Thesis (M.S. in Applied Physics)--Naval Postgraduate School, June 2005. / Thesis Advisor(s): William Colson. Includes bibliographical references (p. 97-98). Also available online.

This thesis focuses on the development of a new technique which enables a novel type of front panel for female body armour to be engineered, providing female contour, high level protection, and therefore comfort in wearing. The traditional cutting and stitching method can be used to form a dome shape to accommodate the bust area but it gives rise to weakness against projectile impact at the seams. A novel type of fabric with the advantage in mouldability is needed as an alternative to the conventional plain woven fabric in making female body armour without the need of cutting or folding but ease in manufacture. Dome-shaped fabric and angle-interlock woven fabric are two potential candidates. The analysis and comparisons determine the selection of the fabric with superior dome depth which is more suitable for the female body armour application. Ballistic evaluations on the selected fabric were carried out from two aspects: the overall ballistic performance investigation and the parametric study. The result provided a better understanding of kinetic energy absorption capability of single-piece selected fabrics. Additionally, the ballistic performance of fabric panels was further evaluated in the factory in order to ensure the selected fabric could achieve the commercial requirement. After the investigations of mouldability and ballistic resistance of the selected fabric, a mathematical model was created, which determines the pattern geometry for the front panel of the female body armour. This mathematical model takes the body figure size and bra size as the input, and the output is the profile of the front panel of female body armour. This work enables the speedy creation of a front panel of the female body armour in the selected fabric. This is an important advance and a novel approach for making seamless female body armour with satisfactory ballistic performance.

The deformation associated with a ballistic shield defeating a projectile can interact with the user’s upper extremity, resulting in the release of the shield, placing those behind the device at risk. This injury mechanism is known as behind-shield blunt trauma (BSBT). Previous studies investigating these interactions have used testing conditions not representative of those present during these behind-shield events and lacked sufficient testing to determine statistically relevant outcomes. In the present work, the loading present during ballistic shield deformation was characterized through testing using an Anthropomorphic Test Device (ATD) upper extremity placed behind a level III ballistic shield. Digital image correlation (DIC) and post-impacting X-ray imaging were used to assess the ballistic shield’s deformation. The data collected from ballistic testing informed the development of a projectile used with a pneumatic impactor for the application of BSBT in a lab-based setting. Using the projectile, ballistic impacts were replicated on the ATD upper extremity and translated to 5th and 95th percentile cadaveric arms. Load data were collected for the hand and forearm using piezoelectric force sensors embedded in the projectile. Similarly, PMHS were impacted in a stepwise fashion of increasing energy until fractures were identified using X-ray imaging. A novel scaling technique was developed where Partial Least Squares (PLS) was used to determine critical variables relating donor anthropometrics to peak impact force. The scaling equations generated using this technique offer future researchers the opportunity to employ a larger range of specimens when determining injury thresholds for the hand and forearm. Through the characterization of the conditions present during BSBT, the injury thresholds to these mechanisms were assessed for understudied populations. Additionally, this work presents scaling techniques that could reduce the number of specimens required to determine future upper extremity injury limits. The information presented within this work provides an important step in developing new standards for ballistic shields to better protect users from BSBT. / Thesis / Master of Applied Science (MASc) / The deformation of a ballistic shield associated with stopping a bullet can interact with the user’s arm, causing them to drop the shield and placing the user in further danger. This work aimed to assess the risks to the hand and forearm over a range of male sizes using mechanical and biomedical tools. Ballistic loading was characterized using a crash test dummy arm to understand the conditions present during the event. The injuries associated with this loading were assessed using cadaveric specimens and a custom projectile for replicating the impacts. Mathematical techniques were used to translate the injury thresholds to the exact user sizes – providing relevant metrics for future ballistic shield standards. The results of this work present methods for recreating ballistic testing in a lab-based setting and for scaling forces associated with the hand and forearm, allowing future researchers to use a broader range of specimens for injury assessment.

We study axisymmetric deformations of depleted uranium (DU) and tungsten heavy alloy (WHA) rods impacting at normal incidence both a rigid, planar target and a thick, deformable steel target. Each deformable material is modeled as elastic thermoviscoplastic; the flow stress increases with an increase in the effective plastic strain and effective plastic strain-rate but decreases with a rise in the temperature. An objective of this work is to ascertain when and where a shear band, defined as a narrow region of rapid, intense plastic deformation, forms in each material subject to impact loading. The Taylor impact simulations show that shear bands form earlier in WHA than in DU for the material parameters used. In the penetration simulations, shear bands form continuously in the ejecta of the DU penetrator while only one shear band occurs in the WHA ejecta followed by more uniform deformations. Note: In order to view the computer animations referenced in this thesis, one must have a QuickTime movie player and download the files named Ujce.mov Uz2e.mov Uz3e.mov Wjce.mov Wz2e.mov and Wz3e.mov from the same directory the "pdf" file resides in. / Master of Science

Approved for public release; distribution is unlimited / Boost phase interception of ballistic missiles is envisioned as the primary response of the layered defense architecture implemented in the ballistic missile defense system. A limited time frame in which to take action and the necessity to implement hit-to-kill technology in the kill vehicle counterbalances the many advantages of boost phase interception. Direct hit missile technology is constrained by the requirement to minimize miss distance to a negligible amount between the kill vehicle and optimum aimpoint on the target. This thesis examines kill vehicle effectiveness, which is tantamount to miss distance, as a function of both the kill vehicle maximum acceleration capability and the guidance system time constant necessary to destroy a target. The kill vehicle guidance system is modeled in MATLAB as a fifth-order binomial series with proportional navigation. The simulation examines the effect of an accelerating target attributed to powered flight and aimpoint displacement caused by a shift in tracking point from the target plume to the payload when resolution occurs. The kill vehicle minimum requirements as indi-cated by the simulation include a lateral acceleration capability of four times the target acceleration and a guidance system time constant that is less than one-tenth the estimated flight time. / Lieutenant, Canadian Navy

Soft body armour is usually constructed by layering numerous layers of the same fabric. Such a construction, however, may not be the most efficient in providing the required protection due to different ballistic resistant efficiency of each layer. This research aims to optimise the construction of the panels for soft body armour by hybridisation in order to achieve the improvement of ballistic performance and reductions in weight. Twaron woven fabrics with different weave structures and Dyneema uni-directional (UD) laminates were used as components for the hybrid design of panels. Two complementary research approaches were employed in this study, namely the empirical method and the Finite Element (FE) analysis. The first part of this research systematically revealed the different ballistic characteristics of each layer in different positions of an armour panel and the way of energy absorption in the panel. The fabric layers in the front, middle and back of the panel exhibited different extent of transverse deformation and stress distribution. The energy absorption increases from front layer and reaches to the maximum value in the last perforated layer and then decreases gradually in the following back layers. Such pattern of energy absorption was not affected by either the striking velocity or the total number of layers in the panel, but the position, in the thickness, of the peak value in energy absorption was shifted more towards the back of the panel when the striking velocity increases. Such findings contribute to the understanding of different ballistic responses in different positions of an armour panel under ballistic impact. The second part of this research put forward a new hybrid design concept. According to above theoretical understandings of different ballistic characteristics in different positions of an armour panel, the fabric layers in the panel were discretely divided into three groups. In addition to the performance of different components for the panel and the influences of the laying sequence, a procedure for constructing hybrid armour panels has been established. The first group was composed of the first few layers on the striking face. The heavyweight fabrics as heat resistant layers were used in this group to resist the heat generated on the striking face. The second group contained some middle layers close to the last perforated layers. The lightweight fabric was combined in this group due to the higher energy absorption capacity. All back layers were classified into the third group. Dyneema UD laminates were placed in this group to constrain the large transverse deflection of the lightweight fabric and to minimize BFS of the panel. Two hybrid panels were designed and evaluated. In the perforation ballistic tests, the hybrid panel was more likely to stop the projectile compared to Twaron woven panels with the same areal density. In the non-perforation ballistic tests, the hybrid panel exhibited significantly lower BFS and achieved the reductions in weight. Such hybrid design makes best use of different available materials to achieve the improvement of ballistic performance and lightweight of a panel. It has a practical significance for the soft armour panel design.

No description available.

Dissertation (Ph.D.)--Auburn University, 2006. / Abstract. Vita. Includes bibliographic references.