Concrete is a widely studied material with a composite nature. It is used both in civil and military buildings and infrastructures. An issue of great importance is the protection of people from terrorist attacks that target critical infrastructure. Explosions, detonations and/or projectile impacts are some of the most severe actions a concrete structure can face. Experimental analysis is necessary in order to understand and predict the response of a structure to such dynamic and strain rate sensitive conditions. However, as the cost of performing experiments is significant and numerical simulations offer improved blast and impact analysis capabilities, there is an effort to limit experiments to validation purposes. In recent years, many researchers have studied the impact loads transferred to reinforced concrete (RC) structures both through direct projectile impacts or blast waves at both near and far field. The aim of the current study is twofold. First, to investigate contact detonations on this type of material (RC), since literature can provide us with limited information. Secondly, to assess the behaviour of the RC structure under combined ballistic impact and contact detonation of a very specific geometry of projectile (HESH) that exists currently on the market and behaves differently from the normal projectiles that consist of one single material. The author analysed and discussed in depth the response of RC members exposed to contact detonations. More precisely, the effect of the mass of explosive (C4) on pressures, impulses and energy balances. Also, she investigated the kinematic response of RC slabs and the structural role of the reinforcing bars. The driving force of this RC structures. Currently, the majority of studies regarding contact blast are focusing either on innovative types of concrete or normal concrete. However, normal concrete is investigated as a control parameter (to prove the effective resistance of the innovative material) rather than a detailed study on the behaviour of the material. Thereafter, the author analysed the response of a RC wall under the combined effect of kinetic energy (terminal ballistics) and contact detonation caused by the impact of a 90 mm HESH (High Explosive Squash Head) projectile fired from a distance of 70 m. The aim was to investigate the response of the structural member under the superposition of those two actions and analyse the combined effects of the impact velocity and detonation on the response of the structure. The numerical modelling is based on a Multi-Material-Arbitrary-Lagrangian-Eulerian approach (MMALE, using LS-DYNA) using the Winfrith concrete constitutive material model to investigate the dynamic response of the RC members under high strain rate conditions. The efficiency of the proposed numerical modelling is validated with experimental results - based on open-arena testing - and provided by the Royal Military Academy of Belgium. Some of the key findings of this research are that the increase of the amount of the explosive affects the damage failure of the RC members from flexural failure to shear failure. In addition, fitting curves that could be used in design, were proposed, that show the relation between the mass of explosive and the resulting pressures and impulses, within the tested range. In the case of the combined blast and impact scenario, the detonation was found to dominate the structural response of the RC slab.

Submitted by Silvana Teresinha Dornelles Studzinski (sstudzinski) on 2016-06-28T16:09:30Z No. of bitstreams: 1 Osvaldo André Oliveira_.pdf: 10816055 bytes, checksum: 50384491a058f8b9850dc0b8c392cd05 (MD5) / Made available in DSpace on 2016-06-28T16:09:30Z (GMT). No. of bitstreams: 1 Osvaldo André Oliveira_.pdf: 10816055 bytes, checksum: 50384491a058f8b9850dc0b8c392cd05 (MD5) Previous issue date: 2014-11-17 / UNISINOS - Universidade do Vale do Rio dos Sinos / Nos últimos 40 anos, estudos arqueológicos (sintetizados em Oliveira et al., 2003; Oliveira e Teixeira, 2005 a,b e c; Oliveira, 2006) apontam que a principal ocupação humana pré-colonial da planície costeira do extremo Sul do Brasil, na região dos municípios de Santa Vitória do Palmar e Chuí, estaria relacionada a grupos construtores de cerritos. Por outro lado, os sítios arqueológicos registrados através do “Banco de Dados Arqueológicos e Paleontológicos do Litoral Sudeste do Rio Grande do Sul, Brasil (BDAP)”, segundo Oliveira (2006), mostram que nesta área também existem outros tipos de sítios, associados a populações e momentos cronológicos distintos, tais como sítios erodidos sobre dunas (localizados na faixa litorânea) e sítios de encosta (nas bordas de banhados da Lagoa Mangueira). Além desses, ocorrem também sítios até agora pouco conhecidos e não estudados, que são o foco de estudo dessa tese, localizados na margem leste da Lagoa Mirim, constituindo-se basicamente de material lítico lascado, com significativa ocorrência de pontas de projétil, que foram denominados sítios líticos da margem da Lagoa Mirim. A região, como um todo, é caracterizada (Villwock e Tomazzelli, 1995) como uma ampla planície costeira, onde campos, banhados, lagoas e áreas úmidas associadas constituem a paisagem dominante. No município de Santa Vitória do Palmar, as margens da Lagoa Mirim ocupam toda a extensão de seu território até limites com o município de Rio Grande (ao Norte) e, através do arroio São Luiz e alagados (ao Sul), faz fronteira com o Uruguai. A partir de cronologias estabelecidas por vários autores (Schmitz et al, 1991; Mentz Ribeiro, 1999; Consens, 2004 entre outros) para a ocupação inicial desses grupos caçadores e coletores na região sul do Brasil e norte do Uruguai, acreditamos que a ocupação dos sítios líticos da margem da Lagoa Mirim tenha se dado entre 10.000 a 6.000 anos A. P., ao final de um período de intensa regressão marinha, que teve seu auge por volta de 18/17.000 A.P., no qual o Sistema Lagunar Patos-Mirim (dentro dele a Lagoa Mirim) havia se transformado em uma larga planície fluvial, onde rios como Jaguarão, Cebolatti, Taquari entre outros, dissecavam os antigos depósitos marinho-lagunares, formando pequenos vales (Villwock e Tomazzelli, 1995). Esses grupos teriam se estabelecido às margens daqueles paleovales, que convergiam para a porção nordeste da atual lagoa, antes de desaguarem no oceano, através da região do atual Banhado do Taim. Esses grupos, possivelmente oriundos da região do vale do Rio Negro, no atual Uruguai, teriam encontrado ali condições adequadas para desenvolverem seu modo de vida. A partir do pico transgressivo holocênico, por volta de 5.000 A.P., os vales são novamente afogados e inicia-se um novo ciclo de formação da paleolaguna Mirim, até ser novamente isolada, formando a lagoa como hoje a conhecemos. A partir desse momento, um novo ciclo de ocupação se desenvolve, com os construtores de cerritos, nas áreas alagadiças ao longo de arroios, nos terraços da recém-formada Lagoa da Mangueira e nas áreas de campos de dunas, na costa. / In the last four decades, archaeological research (synthesized in Oliveira et al. 2003; Oliveira and Teixeira, 2005a,b; Oliveira 2006) points out that the main precolonial inhabitants of the southern coastal plains of Brazil, in the region of Santa Vitória do Palmar and Chuí, was the constructors of earth mounds, locally known as cerritos, of the Vieira tradition. However, the archaeological sites recorded by the “Banco de Dados Arqueológicos e Paleontológicos do Litoral Sudeste do Rio Grande do Sul, Brasil (BDAP)”, according to Oliveira (2006) shows that there would have been another types of sites, associated to different populations and distinctive chronological moments, such as eroded sites over sand dunes (located in the coastal zone) and slope sites, located in the fringes of Lagoa Mangueira marshes. Besides of them, there are also sites that are, until now, poor known and no research have been made until now, wich are the focus of this study. The sites, located along the oriental margin of the Lagoa Mirim, are composed basically by flaked lithic material with significant presence of projectile points. The region, as a whole, is characterized (Villwock and Tomazelli, 1995) as a large coastal plain where grasslands, marshes, lagoons and moist areas conform the dominant landscape. In Santa Vitória do Palmar, the fringes of the Lagoa Mirim occupy all the extension of its territory up to Rio Grande (at North) as far as the Uruguai border (at South). Given the stablished chronologies by various authors (such as Schmitz et al., 1991; Mentz Ribeiro, 1999 and Consens, 2004 among others) to the inicial occupation of the Southern Brazil and northern Uruguai by hunters and gatherers with projectile poits, we believe that the occupation of the lithic sites in the oriental fringes of the Lagoa Mirim takes place between 10.000 to 6.000 years B. P., at the end of an intensive marine regression that reached its height at about 18/17.000 years B. P., in wich the Patos-Mirim lagune system changed into a large aluvial plain, where rivers such as Jaguarão, Cebolatti, Taquari among others run over ancients marine-lagune deposits, forming small valleys (Villwock and Tomazzelli, 1995). This groups would have stablished in the terraces of the paleovalleys that converged to the northeast of the present lake, before to drain at the Atlantic Ocean, through the present Banhado do Taim. These groups, possibly derived of the valley of Rio Negro region, have found in that place suitable conditions to develop their way of life. As from the holocenic transgressive height, at about 5.000 years B. P., the valleys are again drowned and starts a new cycle of formation of the Mirim paleolake, until it be isolated, forming the lake as we know today. From now on, a new cycle of human occupation also develops, with the cerrito builders in the marsh areas along creeks and streams, in the terraces of the newly formed Lagoa Mangueira and in the sand dune fields of the atlantic coast.

The Land Hill and Hidden Hills study areas were the site of the 2006 and 2007 Brigham Young University's archaeological field schools. The two study areas are located in contrasting environments; the Land Hill area is located along the Santa Clara River in southwestern Utah, and the Hidden Hills area was is located on the Shivwits Plateau in northwestern Arizona. The Land Hill study area is located within a well-watered environment which would support a primarily horticultural lifestyle. The Hidden Hills study area is located in an arid environment without permanent streams which would support a more mobile hunting lifestyle. The contrasting environments of these two study areas allowed for a study of the similarities and differences in the use of stone tools. Based on the results of the analysis and comparison of the stone tool and debitage assemblages, from sites in both areas throughout time, suggests that the people in the Land Hills study area actually seemed to be living a lifestyle similar to the people in the Hidden Hills area.

<p>Ceramics constitute an important group of low-density armour materials. Their high intrinsic strength makes it possible to design ceramic armour systems capable of defeating projectiles directly on the ceramic surface. This capability, named interface defeat, signifies that the projectile material is forced to flow radially outwards on the surface of the ceramic without penetrating significantly.</p><p>This thesis presents impact experiments between long-rod projectiles and ceramic targets. The projectile/target interaction was studied using flash X-ray technique. Transition velocities (the impact velocity at which interface defeat can no longer be maintained and penetration starts) were estimated for different combinations of metallic projectiles and ceramic targets and compared to critical velocities estimated on a theoretical basis. Replica scaling experiments were also performed in order to investigate the possible influence of scale.</p><p>All ceramic materials tested showed a distinct transition from interface defeat to penetration. Experiments with different silicon carbides showed that the transition velocity correlated better with the fracture toughness than with the hardness of the ceramic materials. For conical projectiles, penetration occurred along a conical surface crack and at a lower transition velocity than that observed for cylindrical projectiles. Experiments with unconfined alumina targets in different scales showed only a slight increase in dimensionless final penetration with length scale.</p><p>A unique transition velocity seems to exist for each combination of projectile, target material and target configuration. This velocity was found to depend on both the strength (hardness) and the brittleness (fracture toughness) of the ceramic. The lower transition velocity of conical projectiles compared with cylindrical ones is mainly due to the radially expanding load and the penetration of projectile material into surface cracks. The results of the experiments in different scales indicate that replica scaling is valid for penetration in ceramics.</p>

In the past, archaeological investigations have recovered material culture that have often been stored as museum property without a focused analysis or written report of the results. This study focuses on one such assemblage ofchipped stone projectile points from the Bachman Cave locality of southwestern Idaho that has been stored at the Southwest Idaho Regional Archaeological Center (SWIRAC) for over twenty years. The focus of this study outlines the approach used to develop the cultural chronology of the site by conducting an objective and subjective analysis of the projectile points, using previous and recent literature as well as field notes, level records, and published radiocarbon samples to corroborate the data. Overall, this study presents a cultural sequence of a site in southwestern Idaho as it is revealed by the identification and analysis of Bachman Cave projectile points. The Bachman Cave projectile point database is consistent with a known analytical scheme and this will greatly add to future archaeological investigations conducted in the Snake River Plain of Idaho and the Northern Great Basin region. / Graduation date: 2003

<p>Detta arbete handlar om med vilka material som det ballistiska skyddet mot finkalibriga projektiler kan förbättras på befintliga svenska ytstridsfartyg. Eftersom det befintliga fartygets konstruktion i sig innehar en viss skyddsförmåga (grundskydd) behöver denna inledningsvis beskrivas för att definiera utgångspunkt.</p><p>Att förbättra skyddsförmågan genom att komplettera den redan befintliga konstruktionen med tilläggsskydd innebär att fartyg får helt förändrade förutsättningar att klara av nya hot och uppgifter och därmed också få en förbättrad livslängd.</p><p>Genom att studera för- och nackdelar hos olika tekniska lösningar framkommer vilka som är realistiska.</p><p>Fartyg kommer sannolikt att utrustas med olika material eftersom ytor- och utrymmen kommer att behöva prioriteras. Olika materialval kommer också att styras av kompromisser mellan ballistiskt skydd och lastbärande konstruktioner.</p> / <p>This paper investigates which technical solutions can improve ballistic protection against small arm projectiles onboard Swedish naval surface warships.</p><p>Since the construction of the ship itself has a basic protection against projectiles, this will be described first.</p><p>By improving the protection capability with extra protection (supplementary protection), the ship can successfully handle several new threats that come with new tasks while also improving its length of life.</p><p>A study of advantages and disadvantages of different technical solutions will show which solutions are realistic ones.</p><p>The ship will probably be equipped with different kind of materials because of the need of prioritized areas and surfaces onboard. Different materials will be a compromise between the ballistic protection ability and construction strength.</p> / ChpT 08-10

Ceramics constitute an important group of low-density armour materials. Their high intrinsic strength makes it possible to design ceramic armour systems capable of defeating projectiles directly on the ceramic surface. This capability, named interface defeat, signifies that the projectile material is forced to flow radially outwards on the surface of the ceramic without penetrating significantly. This thesis presents impact experiments between long-rod projectiles and ceramic targets. The projectile/target interaction was studied using flash X-ray technique. Transition velocities (the impact velocity at which interface defeat can no longer be maintained and penetration starts) were estimated for different combinations of metallic projectiles and ceramic targets and compared to critical velocities estimated on a theoretical basis. Replica scaling experiments were also performed in order to investigate the possible influence of scale. All ceramic materials tested showed a distinct transition from interface defeat to penetration. Experiments with different silicon carbides showed that the transition velocity correlated better with the fracture toughness than with the hardness of the ceramic materials. For conical projectiles, penetration occurred along a conical surface crack and at a lower transition velocity than that observed for cylindrical projectiles. Experiments with unconfined alumina targets in different scales showed only a slight increase in dimensionless final penetration with length scale. A unique transition velocity seems to exist for each combination of projectile, target material and target configuration. This velocity was found to depend on both the strength (hardness) and the brittleness (fracture toughness) of the ceramic. The lower transition velocity of conical projectiles compared with cylindrical ones is mainly due to the radially expanding load and the penetration of projectile material into surface cracks. The results of the experiments in different scales indicate that replica scaling is valid for penetration in ceramics.

The purpose of this thesis is to gain understanding of the load on flat target surfaces produced by projectile impact. Models are proposed from which upper and lower bounds can be derived for the transition be-tween interface defeat and normal penetration. It is shown that the dominating contribution to the normal load is generally provided by the hydrodynamic pressure due to the effect of inertia. In addition it is shown that the contributions from yield strength and compressibility are also significant. For a cylindrical tungsten alloy projectile at an impact velocity representative of to-day’s ordnance velocities, the contributions to the load intensity on the axis of symmetry from yield strength and compressibility are shown to be 15% and 3.4%, respectively, of that of inertia. Impact tests have shown that for conical projectiles transition from interface defeat to penetration occurs at a significantly lower impact velocity than for cylindrical projectiles. In order to better understand the influence of projectile shape, a conical projectile in axi-symmetric impact is studied by use of an analytical model for self-similar flow, and the results obtained are compared to results of numerical simula-tions. It is shown how the maximum load intensity, and the position of the maximum, depends on the apex angle. For an apex angle of 90º, the maximum load intensity is found to be almost three times that pro-duced by a cylindrical projectile with the same impact velocity. This maximum occurs well off the axis of symmetry and is 20% larger than the load intensity at this axis. Both the self-similar model and the nu-merical simulations show that the contribution to the load intensity from compressibility is positive below and negative above an apex angle of around 80º. The contribution of yield strength to the load in-tensity at centre of impact depends only weakly on the apex angle and is therefore similar to that of a cylindrical projectile.

Detta arbete handlar om med vilka material som det ballistiska skyddet mot finkalibriga projektiler kan förbättras på befintliga svenska ytstridsfartyg. Eftersom det befintliga fartygets konstruktion i sig innehar en viss skyddsförmåga (grundskydd) behöver denna inledningsvis beskrivas för att definiera utgångspunkt. Att förbättra skyddsförmågan genom att komplettera den redan befintliga konstruktionen med tilläggsskydd innebär att fartyg får helt förändrade förutsättningar att klara av nya hot och uppgifter och därmed också få en förbättrad livslängd. Genom att studera för- och nackdelar hos olika tekniska lösningar framkommer vilka som är realistiska. Fartyg kommer sannolikt att utrustas med olika material eftersom ytor- och utrymmen kommer att behöva prioriteras. Olika materialval kommer också att styras av kompromisser mellan ballistiskt skydd och lastbärande konstruktioner. / This paper investigates which technical solutions can improve ballistic protection against small arm projectiles onboard Swedish naval surface warships. Since the construction of the ship itself has a basic protection against projectiles, this will be described first. By improving the protection capability with extra protection (supplementary protection), the ship can successfully handle several new threats that come with new tasks while also improving its length of life. A study of advantages and disadvantages of different technical solutions will show which solutions are realistic ones. The ship will probably be equipped with different kind of materials because of the need of prioritized areas and surfaces onboard. Different materials will be a compromise between the ballistic protection ability and construction strength. / ChpT 08-10

This dissertation focuses on two portions of the Clovis lithic assemblage recovered from Excavation Area 8 at the Gault site (41BL323) located in central Texas. Gault is a quarry-camp visited by hunter-gatherer groups for at least 13,000 years, with Paleoindian, Archaic, and Late Prehistoric occupations. Freshwater seep springs, a diverse array of floral and faunal resources, and an abundant outcrop of high-quality toolstone at the site created an ideal location for people who lived a mobile hunting-andgathering way of life. The site is currently the only locale with two stratigraphically separate Clovis components-a lower geologic unit designated 3a and an upper unit designated 3b. Both are represented in Excavation Area 8 where, in the spring of 2000, Texas A&M University (TAMU) excavated 22 1-m2 contiguous units. For this research, 3375 complete flakes were analyzed individually to characterize Clovis debitage as represented at Excavation Area 8 and to establish if there are technological differences between the debitage assemblages recovered from Units 3a and 3b. The two Clovis components are quite similar from a technological standpoint. Minor differences appear to be related to site formation processes and intensity of site use. The second objective was to determine if Clovis debitage has diagnostic technological traits that allow confident assignment to the Clovis era. To test whether Clovis debitage is distinctive, it was compared to debitage recovered from later cultural components at the site. No evidence of a true blade technology was observed in the post- Clovis Paleoindian or Early Archaic debitage assemblages, although biface manufacture continued through time. Technologically, few differences were observed between the Clovis, post-Clovis Paleoindian, and Early Archaic debitage related to biface reduction. While overshot flakes may be diagnostic of Clovis biface technology, biface thinning flakes and other non-distinctive debitage showed few differences between components. During debitage analysis pieces were selected in an attempt to identify edgemodified tools. Low- and high-power usewear analysis was employed to make determinations concerning the cultural modification or use of flakes. This study concluded post-depositional damage affected most of the collection and there was minimal usewear-or minimal observable usewear-on flakes. Taphonomic processes interfered to a great extent with drawing firm inferences on tool use and possibly hindered the identification of tools. Of the 3375 pieces of Clovis debitage originally analyzed, 26 specimens were classified as tools based mainly on invasive, patterned flaking with less reliance on microscopic use indicators. Of these, inference of use was assigned to nine tools.