DEVELOPMENT, PARAMETERIZATION AND VALIDATION OF DYNAMIC MATERIAL MODELS FOR SOIL AND TRANSPARENT ARMOR GLASS

Despite the signing of several mine ban treaties in the 1990\u27s, it is widely recognized that there is a landmine crisis. The following are some of the main aspects of this crisis: (a) Millions of unexploded landmines remain deployed all over the world; (b) Thousands of civilians are killed or maimed every year by unintended detonations of the mines; (c) The cost of medical treatment of landmine injuries runs into the millions; (d) the ability of the international community to provide the humanitarian relief in terms of medical services, safe drinking water and food, etc., is greatly hampered by landmine contamination of the infrastructure in mine affected countries; and so on. To address the aforementioned landmine crisis, the research community around the world has taken upon itself the challenge of helping better understand the key phenomena associated with landmine detonation and interaction between detonation products, mine fragments and soil ejecta with the targets (people, structures and vehicles). Such improved understanding will help automotive manufacturers to design and fabricate personnel carriers with higher landmine-detonation survivability characteristics and a larger level of protection for the onboard personnel. In addition, the manufacturer of demining equipment and personnel protection gear used in landmine clearing are expected to benefit from a better understanding of the landmine detonation-related phenomena. The landmine detonation-related research activity can be broadly divided into three main categories: (a) shock and blast wave mechanics and dynamics including landmine detonation phenomena and large-deformation/high-deformation rate constitutive models for the attendant materials (high explosive, air, soil, etc.); (b) the kinematic and structural response of the target to blast loading including the role of target design and use of blast attenuation materials; and (c) vulnerability of human beings to post-detonation phenomena such as high blast pressures, spall fragments and large vertical and lateral accelerations. The present work falls primarily into the category (a) of the research listed above since it emphasizes the development of a large-deformation/high-deformation rate material model for soil. It is generally recognized that the properties of soil, into which a landmine is buried, play an important role in the overall effectiveness/lethality of the landmine regardless of the nature of its deployment (fully-buried, flush-buried or ground-laid). Therefore, in the present work, a series of continuum-level material models for soil of different types has been derived (using available public-domain data and various basic engineering concepts/principles), parameterized and validated against experimental results obtained from standard mine-blast testing techniques. Special attention is paid to improving the understanding of the effects of moisture, clay and gravel content on the different aspects of soil material behavior under blast loading conditions. Specifically, the effect of these soil constituents/conditions on the equation of state, strength and failure modes of the material response is investigated. The results obtained clearly revealed that: (a) the moisture clay and gravel contents of soil can substantially affect the response of soil under blast loading conditions as well as the extent of detonation-induced impulse transferred to the target structure/personnel; (b) over all, the models developed in the present work, when used in transient non-linear dynamics analysis of landmine detonation and detonation product/mine-fragment/ soil-ejecta interaction with the target structures/personnel, yielded results which are in reasonably good agreement with their experimental counterparts