Dissertations / Theses on the topic 'Steel mesh'

This study examines whether woven metal mesh is an appropriate option for usage in beds and what material the mesh should consist of to best be suited for the purpose. The woven steel mesh’s construction was based on a reference model that consists of cross-linked rods and wires. Since the aim of the project was to reach a conclusion of the mesh’s usability in beds, different parameters were examined and taken into consideration. These parameters were the durability of the mesh when carrying human weight, acoustic properties to minimize chatter when lying on the mesh and rolling properties. The durability was examined using COMSOL multiphysics. Acoustics were studied through a literature review and rolling properties were calculated using measurements on the reference model. A material investigation was done in the database software CES EduPack. It was found that steel, stainless steel and aluminum fulfilled the requirements set on durability. Stainless steel was considered too expensive and steel too heavy. Using aluminum halves the weight of the mesh in comparison to steel but doubles the price, in this case however the weight was considered to be a parameter of greater importance overriding price.

Includes bibliographical references.
This report presents the results of an investigation into the suitability of steel-fibre reinforced concrete (SFRC) as a building material. The performance of the SFRC is gauged relative to conventional steel mesh-reinforced concrete. The report begins with the historical background of fibre-reinforcing, its development and diversity in modern times. The theoretical principles governing the strength of SFRC are formulated, followed by an extensive review of factors influencing the fibre's potential and its subsequent effect on the mechanical properties of a concrete matrix. The experimental program is thereafter detailed in two stages: the "Efficiency and Proving Phase" followed by the "Application Phase". The former involves a series of tests to determine the most promising fibre of the five types available, while the latter compares the strength properties of slabs and arches reinforced with this fibre to those reinforced with wire mesh. The test results obtained from the two phases are evaluated and discussed in the succeeding two sections and the report ends with the conclusions drawn and recommendations regarding the effectiveness of SFRC relative to mesh-reinforced concrete.

A utilização da tela de aço como reforço de pavimentos asfálticos no combate ao trincamento por reflexão é uma alternativa utilizada desde 1980 em países europeus. Uma revisão da literatura a respeito de sua utilização na reabilitação de pavimentos asfálticos, mostra que, a sua utilização acaba diminuindo o aparecimento de trincas nas camadas de revestimento, agindo como uma barreira contra a sua propagação, oferece resistência ao cisalhamento especialmente sob elevadas tensões e ainda, melhora a resistência à fadiga contribuindo para a longevidade do pavimento. Entretanto, o potencial de sua utilização tem sido pouco investigado em rodovias brasileiras. Neste contexto, insere-se esta pesquisa com o objetivo de avaliar o efeito do reforço gerado pela inserção da tela em revestimentos asfálticos para o uso em pavimentos flexíveis, com o propósito de tornar as estruturas rodoviárias menos onerosas com consequente aumento da sua vida útil. Para isso, foi realizada uma pesquisa visando à análise do seu desempenho em um trecho experimental localizado na rodovia SP-354, no Estado de São Paulo entre as cidades de Campo Limpo Paulista e Jarinu, fundamentado nas melhores práticas internacionais, recorrendo à observação em campo e laboratório, análise por meio de ensaios de módulo de resiliência e cálculos por retroanálise para verificação do efeito da inserção da tela, ainda propondo, uma metodologia de dimensionamento estrutural de reforço de pavimentos asfálticos considerando a faixa de valores de módulo de resiliência integrados com a tela e o fator de deflexão (K) para cálculo de espessura de reforço. Conclui-se que esta técnica de reforço tem potencial para prolongar a vida útil de revestimentos asfálticos em pavimentos flexíveis, com benefícios também para o desempenho da camada na fase pós-trincamento. Foram obtidos modelos que permitem dimensionar o revestimento asfáltico com o propósito de avaliar o efeito da tela de aço na zona tracionada da camada. Por fim, foi verificada através de um estudo de viabilidade técnica/econômica que a incorporação da tela de aço em pavimentos flexíveis é uma alternativa eficaz e de adequada viabilidade técnica e econômica.
The use of the steel mesh as reinforcement of asphalt pavements to combat reflective cracks by reflection is an alternative used since 1980 in European countries. A review of the literature on the use of the steel mesh in the rehabilitation of asphalt pavements shows that its use prevents the appearance of cracks acting as a barrier against its propagation, offers resistance to shearing especially under high tensions and also improves the resistance to fatigue contributing to the longevity of the pavement. However, the potential if its use has been little investigated in Brazilian highways. In this context this project is to develop a new technology for road construction and rehabilitation. The idea is to use steel mesh reinforcement in asphalt roads in order to make road structures more cost effective by improving the lifetime of new constructed roads and by developing an optimal rehabilitation method for existing roads. For this, a research was performed aiming at the analysis of its performance in an experimental section located on the highway SP-354, in the State of São Paulo between the cities of Campo Limpo Paulista and Jarinu, based on the best international practices, using observation of its behavior in the field and laboratory, analysis by means of resilient modulus tests and calculations by backcalculation to verify the effect of the insertion of the screen, still proposing, a methodology of asphalt pavement design considering the range of integrated resilience module values with the screen and the structural deflection reduction factor (K) admissible for reinforcement projects. It was concluded that this reinforcing technique has potential for improvements crack propagation post-cracking behavior and permanent deformation in the asphalt concrete surfacing layer, with a ten fold increase on fatigue life to be expected. A model was developed that may be employed for pavement design modifying a model based on the use of conventional fatigue laws for the asphalt concrete, if the grid is positioned at the tensile zone of the surfacing layer. Finally, it was verified through a technical / economic study that the incorporation of the steel mesh in flexible pavements is an effective alternative and of adequate technical and economic viability.

Tato Diplomová práce se zabývá vlivem vyztužení na mechanické vlastnosti materiálu pro přípravu snímatelných náhrad. Pro testování byly použity tři sady vzorků: PMMA pryskyřice, PMMA pryskyřice s Dentapreg Mesh výztuží a PMMA pryskyřice vyztužena zesilující síťkou z nerezové oceli.Pro měření chování vzorků při statickém a dynamickém namáhání byl použit třibodový ohybový test a Charpy rázové kladivo. Viskoelastické vlastnostzi byly měřeny dynamicko-mechanickou analýzou (DMA). Skenovací elektronová mikroskopie (SEM) byla použita k charakterizaci lomových ploch. Během statického namáhání vzorků výztuž nehraje důležitou roli v porovnání s nevyztuženou pryskyřicí. Nicméně byl pozorován opačný trend při dymanickém namáhání, kde efekt výzruže rostl v řadě PMMA pryskyřice – síťka z nerezové oceli – Dentapreg Mesh.

As lajes dos tabuleiros de pontes de concreto armado, sejam elas maciças ou executadas com pré-lajes, são elementos estruturais suscetíveis à fadiga, devido às ações a que são submetidas. As pré-lajes, pelo fato de serem resultantes da junção de dois concretos diferentes, torna-se ainda mais suscetível à fadiga. Este trabalho apresenta estudos, ensaios e análise de resultados a respeito do comportamento à fadiga das lajes de pontes de concreto, sejam as maciças ou as executadas com pré-laje, armadas com barras ou telas soldadas. Foram realizados ensaios de fadiga de barra ao ar CA50 f10 mm isoladas e em telas para a construção da Curva de Wöhler nas condições brasileiras. Além disso, foram ensaiadas 23 lajes de concreto, sendo 6 lajes maciças e 17 executadas com prélajes, montadas com diversas configurações de armadura, submetidas a ensaios estáticos e dinâmicos. As configurações de armaduras adotadas nas lajes da pesquisa foram baseadas nas utilizadas com freqüência neste tipo de elemento das pontes, escala ½. Um dos principais motivos que levaram ao desenvolvimento desta pesquisa de caráter experimental foi a escassez de dados sobre o comportamento de lajes armadas com barras ou telas soldadas de fabricação brasileira, submetidas a ações cíclicas. Outro motivo foi a carência de estudos a respeito da iteração prélaje x capa. Foi verificado que não houve ruptura nessa região da estrutura devido aos carregamentos cíclicos aplicados no meio do vão. Ficou evidenciado também que as soldas das telas afetam sua resistência à fadiga.
Concrete bridge slabs, massive or pre-slabs, are structural elements susceptible to fatigue, due to loading applied to them. Pre-slabs, result of two different concretes, become even more susceptible to fatigue. This research presents the studies, tests and analysis of the results about the behavior of concrete bridge massive slabs or pre-slabs reinforced with steel bars and welded steel meshes due to fatigue loading. Axial testing in air of CA50 f10 mm in continuous bars and steel meshes were made in order to build the Wöhler Curve to the Brazilian conditions. Besides that, tests were made in 23 concrete slabs, 6 massive slabs and 17 preslabs, with several reinforcements arrangements, submitted to static and dynamic loading. The reinforcement configurations adopted in the slabs were based on the commonly used in these bridge elements in scale ½. One of main reasons that lead this experimental research development was the scarcity of data about the behavior of concrete slabs reinforced with rebars and welded mesh made in Brazil, submitted to cycle loading. Another reason was the lack of studies about the iteration between pre-slab and concrete cover. It was verified that no rupture was found in this region of the structure due to midspan cycle loading. The welding process caused loss of fatigue resistance.

Vrstva okují, skládající se z oxidů železa, která se tvoří na povrchu oceli při jejím tepelném zpracování, má velký vliv na tepelné metalurgické procesy. Tepelná vodivost okují je jeden z klíčových parametrů pro numerické modelování procesů odkujování a chlazení oceli. Tato vodivost je nicméně silně ovlivňována porézní strukturou okují a žádná všeobecně uznávaná materiálová data nejsou v současnosti dostupná. Cílem této práce bylo provést stacionární tepelnou analýzu za účelem stanovení tepelné vodivosti vrstvy okují. Byl vytvořen podrobný 3D MKP model vrstvy okují založený na datech získaných pomocí CT skenování. Je popsáno získání CT obrazu a jeho zpracování. Využity byly dva různé způsoby segmentace. Pravidelná krychlová výpočetní síť byla vytvořena přímo z voxelové matice zpracovaného CT obrazu. Výsledné hodnoty tepelné vodivosti získané z provedené MKP analýzy byly téměř identické pro obě metody segmentace, což prokazuje jejich vhodnost. Výsledná tepelná vodivost okují může být dále využita jako materiálová charakteristika v numerických modelech tepelného zpracování oceli

Durch die Ergänzung von Organoblechen mit gewebten Strukturen aus Metalldrähten können hochbelastbare Bauteile gleichzeitig mit einer abschirmenden Wirkung versehen werden und ermöglichen so Anwendungen wie beispielsweise im Umfeld der Elektromobilität. Im Rahmen der vorliegenden Arbeit wird ein polypropylen-basierter Schichtverbund aus thermoplastischen Hochleistungsfaserverbunden und Metalldrahtgewebe hinsichtlich seiner Eignung zur Abschirmung elektromagnetischer Wellen für Gehäusestrukturen und seiner Verarbeitbarkeit im Spritzgießen näher analysiert. Die Untersuchungen zeigen den Einfluss von Defekten, wie sie bei der Herstellung realer Bauteile entstehen können, und deren Auswirkung auf die Abschirmwirkung des Bauteils. Darüber hinaus werden mit Vibrations-,Infrarot- und Heißgasschweißen mögliche Fügeverfahren aufgezeigt und hinsichtlich ihrer Abschirmwirkung bewertet, die auch eine elektrische Kontaktierung über die Fügestelle hinweg ermöglichen.:1 Einleitung 2 Grundlagen 3 Experimentelles 4 Analyseverfahren 5 Untersuchungsergebnisse 6 Zusammenfassende Bewertung der Ergebnisse 7 Zusammenfassung
By combining endless glass fiber reinforced thermoplastic semifinished products with embedded metal wire meshes it is possible to produce highly stressable parts, which additionally allow shielding of electromagnetic waves. Therefore these party can be used for electric cars. In this study a multi-layer film, consisting of polypropylene-based organosheets, PPGF30 and metal wire meshes, is analyzed regarding its suitability for shielding against electromagnetic waves and its processability in injection molding. The analysis show the influences defects, which accure during the production of housings, and their impact of the shielding effectiveness. Moreover possible joining technologies, such as infraredwelding, vibrationwelding and ultrasonicwelding, are studied and evaluated whether it’s possible to create a electrically conductive joint.:1 Einleitung 2 Grundlagen 3 Experimentelles 4 Analyseverfahren 5 Untersuchungsergebnisse 6 Zusammenfassende Bewertung der Ergebnisse 7 Zusammenfassung

Este trabalho apresenta uma estratégia numérica desenvolvida usando o método dos elementos finitos para simular o processo de falha de compósitos cimentícios reforçados com fibras de aço. O material é descrito como um compósito composto por três fases: matriz cimentícia (pasta, argamassa ou concreto), fibras descontínuas discretas, e interface fibra-matriz. Um novo esquema de acoplamento para malhas de elementos finitos não-conformes foi desenvolvido para acoplar as malhas geradas independentes, da matriz cimentícia e de uma nuvem de fibras de aço, baseado na utilização de novos elementos finitos desenvolvidos, denominados elementos finitos de acoplamento. Utilizando este esquema de acoplamento, um procedimento não-rígido é proposto para a modelagem do complexo comportamento não linear da interface fibra-matriz, utilizando um modelo constitutivo de dano apropriado para descrever a relação entre a tensão de cisalhamento (tensão de aderência) e deslizamento relativo entre a matriz e cada fibra de aço individualmente. Este esquema também foi adotado para considerar a presença de barras de aço para as análises de estruturas de concreto armado. As fibras de aço são modeladas usando elementos finitos lineares com dois nós (elementos de treliça) com modelo material elastoplástico. As fibras são posicionadas usando uma distribuição randômica uniforme isotrópica, considerando o efeito parede. Uma abordagem contínua e outra descontínua são investigadas para a modelagem do comportamento frágil da matriz cimentícia. Para a primeira, é utilizado um modelo de dano isotrópico com duas variáveis de dano para descrever o comportamento de dano à tração e à compressão. A segunda emprega uma técnica de fragmentação de malha que utiliza elementos finitos degenerados, posicionados entre todos os elementos finitos que formam a matriz cimentícia. Para esta técnica é proposto um modelo constitutivo à tração, compatível com a abordagem descontínua forte contínua, para prever a propagação de fissura. Para acelerar o cálculo e aumentar a robustez dos modelos de dano contínuos para simular o processamento de falhas, um esquema de integração implícito-explícito é utilizado. Exemplos numéricos são apresentados ao longo do desenvolvimento desta tese. Inicialmente, exemplos numéricos com um único reforço são apresentados para validar a técnica desenvolvida e para investigar à influência das propriedades geométricas 7 das fibras e sua posição em relação à superfície de falha. Posteriormente, exemplos mais complexos são considerados envolvendo uma nuvem de fibras. Nestes casos, atenção especial é dada à influência da distribuição das fibras no comportamento do compósito relacionado ao processo de fissuração. Comparações com resultados experimentais demonstram que a aplicação da ferramenta numérica para modelar o comportamento de compósitos cimentícios reforçados com fibras de aço é muito promissora e pode ser utilizada como uma importante ferramenta para melhor entender os efeitos dos diferentes aspectos envolvidos no processo de falha deste material.
This work presents a numerical strategy developed using the Finite Element Method (FEM) to simulate the failure process of Steel Fiber Reinforced Cementitious Composites (SFRCCs). The material is described as a composite made up by three phases: a cementitious matrix (paste, mortar or concrete), discrete discontinuous fibers, and a fiber-matrix interface. A novel coupling scheme for non-matching finite element meshes has been developed to couple the independent generated meshes of the bulk cementitious matrix and a cloud of discrete discontinuous fibers based on the use of special finite elements developed, termed Coupling Finite Elements (CFEs). Using this approach, a nonrigid coupling procedure is proposed for modeling the complex nonlinear behavior of the fiber-matrix interface by adopting an appropriate constitutive damage model to describe the relation between the shear stress (adherence stress) and the relative sliding between the matrix and each fiber individually. This scheme has also been adopted to account for the presence of regular reinforcing bars in the analysis of reinforced concrete structural elements. The steel fibers are modeled using two-node finite elements (truss elements) with a one-dimensional elastoplastic constitutive model. They are positioned using an isotropic uniform random distribution, considering the wall effect of the mold. Continuous and discontinuous approaches are developed to model the brittle behavior of the bulk cementitious matrix. For the former, an isotropic damage model including two independent scalar damage variables for describing the composite behavior under tension and compression is considered. The discontinuous approach is based on a mesh fragmentation technique that employs degenerated solid finite elements in between all regular (bulk) elements. In this case, a tensile damage constitutive model, compatible with the Continuum Strong Discontinuity Approach (CSDA), is proposed to predict crack propagation. To increase the computability and robustness of the continuum damage models used to simulate the failure processes in both of the strategies, an implicit-explicit integration scheme is used. Numerical analyses are performed throughout the presentation of the work. Initially, numerical examples with a single reinforcement are presented to validate the technique and to investigate the influence of the fibers geometrical properties and its position relative to the crack surface. Then, more complex examples involving a cloud of steel fibers are considered. In these cases, special attention is given to the analysis of the influence of the fiber distribution on the composite behavior relative to the cracking process. Comparisons with experimental results demonstrate that the application of the numerical tool for modeling the behavior of SFRCCs is very promising and may constitute an important tool for better understanding the effects of the different aspects involved in the failure process of this material.

Resume de la these en francais cette these ouvre a nouveau le dossier de la +guerre sainte; dans la bible hebraique par le biais de l'etude de quatre textes envisages deux par deux, un texte biblique etant etudie en rapport avec un document du proche orient ancien : 2 rois chapitre 3 en relation avec la stele de mesha, 2 samuel, chapitre. 20 avec la lettre d'archives royales de mari ii, 48. Chaque texte est tout d'abord envisage en fonction d'une histoire de la redaction puis fait alors l'objet d'une etude structurelle (relative aux procedes rhetoriques) et enfin semiotique (examen des niveaux discursifs, narratifs et logico-semantique). Il en ressort que la stele de mesha illustre la pregnance d'une conception de l'histoire marquee par le motif du retour du dieu kamosh et une apprehension du temps de l'espace fortement redevable a une theologie du dieu national. La version ancienne (preexilique) de 2 r 3 releve de conceptions similaires. Yhwh n'intervient pour son peuple qu'en deca des frontieres de moab dans le cadre d'une +guerre sainte;, ordonnee par le prophete et menee par le peuple. Passe ce seuil, la guerre devient profane. La lettre arm ii, 48 permet de comprendre la version ancienne de 2 sa. 20 comme la denonciation de la violence d'un pouvoir central peu enclin a negocier la solde de troupes auxiliaires. L'insertion dans ce recit ancien du discours de la femme d'abel beth maaka le transforme en apologie du compromis entre pouvoir central et celui des villes. La version actuelle de ce recit est a lire comme un episode de la geste initiatique du guerrier joab rappelant le meurtre du representant de la deuxieme fonction dans les epopees indo- europeennes selon les analyses de g. Dumezil
This thesis reopens the pregnant question of the + holly war ; in the hebrew bible - through the study of four paired textes according to possible similarities when they relates the same or identical events : 2 kings chapter 3 and the stele of mesha, 2 samuel, chapter 20 and a letter from the royal archives of mari (a. R. M. Ii, 48). Each text is first investigated according to an history of the writting then to a structural study (rhetoric processes) and at last to a semiotic point of view. This studies set off that the stele of mesha illustrates the conception of the history impressed by the pattern of the come back of the god kamosh and a concept of times and space deeply dependant on a theology of the national god. The old version (preexilic) of 2 k 3 seems to depend on similaries approaches. Yhwh does not occur within a + holly war ; led by the prophet et performed by the people, except until the boarder of moab. After this threshold, the war is secular again. The letter arm ii, 48 allows to understand the ancient account of 2 sa 20 as the denunciation of the violence of a central power refusing to negociate the pay of auxiliaries troops. The insertion of the discurse of a woman from abel beth maaka turns this old narration into an apology of the compromise between the central power and power of the cities. The present version of this account may be a part of an initiatic epic of the warrior joab closed to the murder of the representative of the second function in the indoeuropean epics according to g. Dumezil analysis

Multiple studies on the microstructures of advanced high-strength steels are presented here that seek to add to the already substantial body of knowledge on martensite in steel. These studies seek to gain additional insight into the role that the martensite transformation has on the observed mechanical properties of modern steels. Crystallographic Reconstruction of Parent Austenite Twin Boundaries in a Lath Martensitic Steel The study of post-transformation microstructures and their properties can be greatly enhanced by studying their dependence on the grain boundary content of parent microstructures. Recent work has extended the crystallographic reconstruction of parent austenite in steels to include the reconstruction of special boundaries, such as annealing twins. These reconstructions present unique challenges, as twinned austenite grains share a subset of possible daughter variant orientations. This gives rise to regions of ambiguity in a reconstruction. A technique for the reconstruction of twin boundaries is presented here that is capable of reconstructing 60 degree <1 1 1> twins, even in the case where twin regions are comprised entirely of variants that are common between the twin and the parent. This technique is demonstrated in the reconstruction of lath martensitic steels. The reconstruction method utilizes a delayed decision-making approach, where a chosen orientation relationship is used to define all possible groupings of daughter grains into possible parents before divisive decisions are made. These overlapping, inclusive groupings (called clusters) are compared to each other individually using their calculated parent austenite orientations and the topographical nature of the overlapping region. These comparisons are used to uncover possible locations of twin boundaries present in the parent austenite. This technique can be applied to future studies on the dependence of post-transformation microstructures on the special grain boundary content of parent microstructures. Coupling Kinetic Monte Carlo and Implicit Finite Element Methods for Predicting the Strain Path Sensitivity of the Mechanically Induced Martensite Transformation The kinetic Monte Carlo method is coupled with a finite-element solver to simulate the nucleation of martensite inside the retained austenite regions of a TRIP (transformation induced plasticity) assisted steel. Nucleation kinetics are expressed as a function of load path and kinematic coupling between retained austenite regions. The model for martensite nucleation incorporates known elements of the kinetics and crystallography of martensite. The dependence of martensite transformation on load path is simulated and compared to published experimental results. The differences in transformation rates of retained austenite are shown to depend on load path through the Magee effect. The effects of average nearest neighbor distance between austenite grains is shown to affect the rate at which martensite nucleates differently depending on load path. Ductility and Strain Localization of Advanced High-Strength Steel in the Presence of a Sheared Edge The localization of strain in the microstructures of DP 980 and TBF 980 is quantified and compared. Of particular interest is the difference in final elongation observed for both materials in the presence of a sheared edge. Scanning electron micrographs of etched microstructures near the sheared edge are gathered for both materials at varying amounts of macroscopic strain. These micrographs are used to generate strain maps using digital image correlation. A two point statistical measure for strain localization is developed that utilizes strain map data to quantify the degree to which strain localizes around the hard phase of both materials. The DP steel exhibits higher strain localization around the martensite phase. Reasons for differences in strain localization and shear banding between the two materials are suggested, and the role played by the mechanically induced martensite transformation is speculated.

The demand for miniature devices has increased the application of hydroforming process in various micro-scale applications. This research ascertain the material properties of 0.2 mm thick AISI 304 stainless steel using hydraulic bulge test, and it also analyze the surface characteristics of the same material. The work pieces for this work consist of circular and elliptical work pieces. The circular work pieces were formed using dies of cavity diameters 5 mm and 11 mm, while the elliptical work pieces were formed using elliptical cavity dies with aspect ratio of 0.5, 0.8, and 0.67. Analytical methods proposed by Chakrabarty, Ekineev-Kruglov, Jovane, and Marciniak for the determination of the flow curve of sheet metal were compared to the experimental result. The outcome indicates that the Ekineev - Kruglov method has the best correlation with the experiment. An improved approach of the Banabic method was developed for the elliptical workpieces, and the results showed shows considerable improvement on the method. Surface characteristics of the 5 mm and 11 mm die work pieces were tested using the atomic force microscope; the outcome demonstrates that most of the surface parameters exhibit a linear relation with the strain. The roughness increase with increasing strain.

Diploma thesis is focused on the description of the parameters of nonlinear material models of concrete, which are implemented in a computational system LS-DYNA, interacting with performance of nonlinear test calculations in system LS-DYNA on selected problems, which are formed mainly by simulations of tests of mechanical and physical properties of concrete in uniaxial compressive and tensile on cylinders with applying different boundary conditions and by simulation of bending slab, with subsequent comparison of some results of test calculations with results of the experiment. The thesis includes creation of appropriate geometric models of selected problems, meshing of these geometric models, description of parameters and application of nonlinear material models of concrete on selected problems, application of loads and boundary conditions on selected problems and performance of nonlinear calculations in a computational system LS-DYNA. Evaluation of results is made on the basis of stress-strain diagrams and load-displacement diagrams based on nonlinear calculations taking into account strain rate effects and on the basis of hysteresis curves based on nonlinear calculations in case of application of cyclic loading on selected problems. Verification of nonlinear material models of concrete is made on the basis of comparison of some results of test calculations with results obtained from the experiment.

碩士
義守大學
材料科學與工程學系
100
Superhydrophobic surfaces (i.e., those with water contact angles of greater than 150°) have attracted a great amount of commercial and academic attention. In recent years, there has been an increased interest in the production and utilization of surfaces exhibiting superhydrophobicity and superoleophilicity for the separation or selective adsorption of oil (or other hydrophobic organic solvents) from water. In this paper, we report a simple and inexpensive method for fabricating superhydrophobic/superoleophilic Zinc Oxide (ZnO)-coated stainless-steel mesh films through hydrothermal reactions. The microstructured ZnO coatings maintain their superhydrophobicity and superoleophilicity after ultraviolet irradiation and display environmental stability. Furthermore, those microstructured ZnO-coated mesh films exhibit good selectivity (even underwater) and excellent recyclability. Such superhydrophobic microstructured ZnO-coated mesh films have potential applications in liquid–liquid separation, water treatment and liquid transportation.

碩士
明志科技大學
材料工程系碩士班
105
In this work, we used the stainless steel (SS) mesh as the substrate, vertically aligned carbon Nanotubes (CNTs) were grown on SS mesh via a home-made thermal chemical vapor deposition (CVD). The as-prepared CNTs/SS meshes were utilized in the application of oil water separation. Due to the three important properties as below, SS meshes were used as the substrate for the study of oil water separation: (1) Anti-corrosion and outstanding mechanical strength to avoid failing by the debris floated on the ocean, (2) easy design for various products, and (3) low cost. We successfully fabricated the high-density and uniform CNTs on the SS meshes, as-inspired Lotus effect by nature plane, our vertically align CNTs showed outstanding performance of superhydrophobicity. The CNTs/SS mesh owning a water contact angle of as high as 144° and an oil contact angle of 0°. It is expected that such superhydrophobic and superoleophilic filtering membrane made by CNTs/SS mesh can be widely used for continous oil-water separation in the practical use. The prepared superhydrophobic and superoleophilic CNTs/SS mesh displayed the outstanding performance in the continuous oil-water separating, including easy fabrication process, low cost, large-area production, reusable ability, and rapid collection of various oils from water.

碩士
國立交通大學
材料科學與工程學系奈米科技碩博士班
101
Recently, one-dimensional nanostructures are a new class of advanced materials that have been receiving a lot of research interest due to their superior physical and chemical properties. In many different kinds of materials, zinc oxide is one of the most important materials and has attracted much attention because of its unique optical, electrical, and piezoelectric properties for versatile applications. The present study proposes a fabrication method to improve the applications of 1D ZnO nanostructures. The well-aligned ZnO nanorods array on the stainless steel mesh can be used in photocatalystic applications. The stainless steel mesh provided an extensive surface area and facilitated efficient mass transfer. The nanorods array exhibited excellent photocatalytic activity and extensive enhanced properties due to high surface to volume ratio for the photodecomposition of a non-biodegradable azo dye. In this thesis, well-aligned ZnO nanorods array were grown on the stainless steel mesh substrate using a solution-based process. First, a ZnO seeds layer was prepared on the stainless steel mesh substrate by thermal decomposition. ZnO nanorods array were grown on the substrate using an aqueous solution method. Finally, the ZnO nanorod-coated substrate was immersed in the different concentration of dye solution and irradiated the UV light (245 nm) for 3 h. The remaining dye in the solution as a function of UV irradiation time was performed by an UV-visible spectrum. The ZnO nanorods array on the stainless steel mesh substrate can be used to irradiate UV light for the photocatalytic degradation of four different models acridine-dye (methylene blue), anthracene-dye (rhodamine 6G), azo-dye (acid Orange 7, methyl orange) and pyridine-dye (4-nitrophenol). Herein, five kinds of dyes used in photocatalysis including colored methylene blue, rhodamine 6G, methyl orange, acid orange 7, and transparent 4-nitrophenol to prove that it can be photocatalyzed in all-band absorbable wavelength. The result exhibits that complete decolorization of the five kinds of dye solution may be achieved. Further tests by different parameters, such as growth times, different size of holes, different size of stainless steel mesh, and different length of nanorods can effectively enhance the photocatalytic efficiency. In addition, the repeatability of ZnO nanorods photocatalysis in dye photodecomposition has been proved. After ten cycles of photodecomposition, the photocatalytic efficiency reduced to about 91% and 86% for methylene blue and rodamine 6G, respectively. The ZnO nanorod arrays on the stainless steel mesh provides a large-scale, facile, low-cost, high surface area, and high photocatalytic efficiency, which shall be of significant value for practical applications of the decomposition of environment pollutants and reusing of wastewater treatment.

碩士
國立臺灣大學
應用力學研究所
107
Fine particulate matter (PM2.5) is a critical and imperative problem in Asia. It has been classified as the 1A carcinogen by The United Nations International Agency for Research on Cancer (IARC). According to the latest TEDS 9.0 (Taiwan Emission Data System 9.0), it shows that oil mist emissions from restaurants account for 6.39% of the total PM2.5 emissions in 2013. This ratio is even higher than power supply industries that only contributes 3.64％ of total emission. For housewives who do not smoke in Taiwan, their risk to develop lung cancer can increase by 3.2% to 12.2% through a long term exposure of oil mist at high temperature. Therefore, an effectively control to oil mist emissions is a very important task nowadays However, common commercial fiber-based filters can be quickly masked by oil mist and are needed to be replaced frequently. In order to prolong the lifetime of the fiber filter, an inertial impactor plate and stainless steel mesh filter are used in this paper. They are less likely to clog when filtering oil mist and oils can be directed for collection by design of oil trenches. Furthermore, a high voltage stainless steel mesh array with a high electric field are also introduced to collect charged particles in the air for long term usage. For the impactor developed in this study, liquid channels are designed in the inertial impactor plate, and the filtered oil droplets are collected and drained in the channel. At the flow rate of 45 cm/s, the oil mist with aerodynamic diameter larger than 6 μm can be filtered. For the particles smaller than aerodynamic diameter of 6 μm can be captured by the multi-layered high-voltage electrostatic mesh filter. A high electric field is applied to the multi-layered mesh filter for improving filtration efficiency. Parameters include the electric field, the number of filter layers, the filtration flow rate and the filter structure. Finally, we developed a 27-layer 100-mesh stainless steel filter driven under 1.4 kV/mm electric field with the optimal performance. At a filtration flow rate of 15 cm/s, the filtration efficiency of particles with particle size larger than 50 nm is above 50%, and the filtration of particles with particle size larger than 120 nm reached 70%. This method provides means to reduce the oil mist loading on the back fiber filter and prolong its lifetime for long term usage.

碩士
國立臺灣大學
應用力學研究所
107
According to the global report of the World Health Organization in 2014, the global population affected by indoor pollution is mainly in Asia and Africa, and it influences about 3 billion people. Due to the lack of ventilation and filtration systems, oil mist generated by cooking kills about 3.5 to 4.3 million people every year. According to TEDS(Taiwan Emission Data System) 9.0, Taiwan''s emissions from restaurants and households account for 6.39% and 17.13% of the total PM2.5 (PM: Particulate matter) emissions. Therefore, how to effectively prevent the inhalation of oil mist become one of the main tasks in the world. In this study, methods to enhance commercial oil-mist filters are proposed and studied. Since the commercial polypropylene (PP) electrostatic filter provides filtration mechanism of electrostatic attraction, it has a higher filtration efficiency for the particle size between 100 to 400 nm. However, captured oil mist can mask PP fibers, and the chargeability and its filtration efficiency can be depleted very quickly. Therefore, a method to modify the surface of PP fibers is developed in this thesis. Nanoparticles are sprayed on the surface of PP fibers to change its surface energy. It was found that spraying PTFE (polytetrafluoroethene) nanoparticles on PP fibers can improve the filtration efficiency and achieve 23.25 % higher performance. Secondly, electric field was introduced to commercial filter by using stainless steel meshes to sandwich these filters. Commercial filters are placed between two stainless steel meshes. It was found that letting the front stainless steel mesh to be positively charged and grounded the other one on the back, the quality factor is 6.46 times higher than no charged stainless steel meshes. It also was found that placing commercial filters sequentially as oleophilic filter at front followed by putting a oleophobic filter behind it can have a better filtration efficiency by 2.47 %. Finally, by placing a high porous TPU (thermoplastic polyurethane) filter in front of all commercial filters, the overall pressure drop can be significantly decreased by 27.36 % and the filtration efficiency can increased by 2.72 %. This design can prolong the usage of commercial filters for oil mist filtrations and also decrease the system pressure drop.

In several practical applications, hot-finished steel pipe that exhibits Lüders bands is bent to strains of 2-3%. Lüders banding is a material instability that leads to inhomogeneous plastic deformation in the range of 1-4%. This work investigates the influence of Lüders banding on the inelastic response and stability of tubes under rotation controlled pure bending. It starts with the results of an experimental study involving tubes of several diameter-to-thickness ratios in the range of 33.2 to 14.7 and Lüders strains of 1.8% to 2.7%. In all cases, the initial elastic regime terminates at a local moment maximum and the local nucleation of narrow angled Lüders bands of higher strain on the tension and compression sides of the tube. As the rotation continues, the bands multiply and spread axially causing the affected zone to bend to a higher curvature while the rest of the tube is still at the curvature corresponding to the initial moment maximum. With further rotation of the ends, the higher curvature zone(s) gradually spreads while the moment remains essentially unchanged. For relatively low D/t tubes and/or short Lüders strains, the whole tube eventually is deformed to the higher curvature entering the usual hardening regime. Subsequently it continues to deform uniformly until the usual limit moment instability is reached. For high D/t tubes and/or materials with longer Lüders strains, the propagation of the larger curvature is interrupted by collapse when a critical length is Lüders deformed leaving behind part of the structure essentially undeformed. The higher the D/t and/or the longer the Lüders strain is, the shorter the critical length. This class of problems is analyzed using 3D finite elements while the material is modeled as an elastic-plastic solid with an “up-down-up” response over the extent of the Lüders strain, followed by hardening. The analysis reproduces the main features of the mechanical behavior provided the unstable part of the response is suitably calibrated. The uniform curvature elastic regime terminates with the nucleation of localized banded deformation. The bands appear in pockets on the most deformed sites of the tube and propagate into the hitherto intact part of the structure while the moment remains essentially unchanged. The Lüders-deformed section has a higher curvature, ovalizes more than the rest of the tube, and develops wrinkles with a characteristic wavelength. For every tube D/t there exists a threshold of Lüders strain separating the two types of behavior. This bounding value of Lüders strain was studied parametrically.
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A novel electrode was constructed and tested in a bio-battery. This configuration consisted of a composite electrode with immobilized bacteria (Escherichia coli K-12) in the anode and a composite electrode with immobilized Carbon Nanoparticles (CNP) and algae (Chlorella vulgaris/Scenedesmus sp.) suspended in the cathode. The composite electrode consisted of three parts: a 304L stainless steel mesh base, an electro-polymerized layer of pyrrole, and an electro-polymerized layer of methylene blue. The bacteria were immobilized on the anode electrode using a technique incorporating CNP and a Teflontm emulsion. The anode and cathode electrodes were tested separately in conjunction with chemical cathodes and anodes respectively. The composite electrode with immobilized bacteria was tested in a bioanode setup. The cathode chamber of the cell contained a potassium ferricyanide and buffer solution with a graphite electrode. Factors affecting electrode performance, such as Teflontm and carbon nanoparticle concentration, were investigated to find optimum values. The maximum power density generated by the composite electrode with immobilized bacteria and a chemical cathode was 378 mW/m2. This electrode configuration produced approximately 69% more power density and 53% more current density than composite electrodes with bacteria suspended in solution. Electrochemical Impedance Spectroscopy analysis determined that a significant portion of the bio-battery’s resistance to charge transfer occurred at the surface of the anode and this resistance was significantly lowered when using immobilized bacteria (51% lower than bio-batteries with suspended bacteria). Similarly, biocathodes containing composite electrodes coated with CNP were tested using two algae species, Chlorella vulgaris and Scenedesmus sp., suspended in solution. This electrode configuration was compared with composite electrode without CNP coating. The anode chamber contained potassium ferrocyanide solution with a graphite counter electrode. The composite electrode with CNP produced approximately 23% more current density than composite electrode without CNP. A complete bio-battery was designed using a composite electrode with immobilized bacteria anode and a CNP coated composite electrode with algae suspended in the cathode. EIS analysis showed that the resistance was higher in the biocathode than in the bioanode and a significant portion of the ohmic resistance was contributed by the membrane.

>Magister Scientiae - MSc
In recent times, the occurrence and presence of complex recalcitrant toxic contaminants in water and wastewater is increasing and consequently contributes to the non-availability of clean and safe drinking water. Water treatment is complex, time demanding and energy intensive due to the physico-chemical structural complexity and diversity of the pollutants. Non-availability of good drinking water has negatively affected human health and the ecosystem. Over the years, numerous conventional treatment techniques were used to degrade and remove these pollutants, but investigations indicated that some of the pollutants are not susceptible to conventional treatment. Advanced oxidation technology, among which heterogeneous photocatalysis (involving the use of a semiconductor) has emerged as one of the more promising techniques to remediate contaminated water. Titanium dioxide (TiO2) semiconductor photocatalysis is considered to be a good option due to its cost effectiveness, chemical and thermal stability, and inertness in the area of wastewater reclamation and re-use. However the post separation of the titania particles poses a threat to the wastewater remediation. Hence there is a need to develop a supported high surface area photocatalyst that will resolve the post separation challenge. This present study aimed to prepare high surface area TiO2 anatase nanocrystals supported on a stainless steel mesh. These new composite materials were used to remove methylene blue (MB) from aqueous solutions. The supporting procedure involved the thermal decomposition of a sol gel solution coated upon stainless steel mesh. The nanocrystalline anatase phase was formed by thermal decomposition on a stainless steel mesh coated with 8 % PAN/DMF/TiO2 sol gel formation calcined at varying temperatures of 300 °C, 400 °C, 500 °C and 600 °C. The heating rate of 50 °C/min and independent holding time of 1 h, 2 h, 3 h and 4 h were applied to find the optimum supporting conditions. The synthesised TiO2 nanocomposites materials were characterised using the following analytical techniques: XRD, HRSEM, EDS, HRTEM, SAED, FTIR and UV-Vis absorption spectroscopy materials were characterised, and the results indicate that synthesised TiO2 nanocrystals were in the anatase form, polycrystalline in nature, and contained additional carbon-carbon bonds from the polymer used during preparation with TiO2 particle sizes range from 13.6 nm to 2285 nm.

Natural fiber-reinforced composites are now finding extensive uses in various fields from household articles to automobiles. These composites can score high compared to common synthetic fiber-based composites, notably glass fiber-reinforced composites, in areas such as occupational safety and health, and impact on environment. The current research work is motivated by the need for exploring jute fibers as replacement for glass fibers for various engineering design applications including more demanding impact protection applications as in automotive body structures. In the current work, detailed mechanical characterization of jute-polyester (JP) composite laminates till failure has been carried out for tensile, compressive and flexural loads by varying volume fraction of jute fibers. The effect of fiber volume fraction on mechanical properties is shown. Because of the potency of closed thin-walled components as structural energy-absorbers, a comprehensive experimental study has been performed, for the first time, comparing the behaviors of various geometric sections of JP and glass-polyester (GP) composite tubes under axial quasi-static and low velocity impact loading. Additionally, for jute-reinforced plastic panels to be feasible solutions for applications such as automotive interior trim panels, laminates made of such materials should have adequate perforation resistance. Thus, a detailed comparative study has been carried out for assessing the performance of JP laminates vis-a-vis GP plates under low velocity impact perforation conditions. As high-end product design is heavily driven by CAE (Computer-Aided Engineering), the current research work has also focused on the challenging task of developing reliable modeling procedures for explicit finite element analysis using LS-DYNA for predicting load-displacement responses and failures of JP composites under quasi-static and impact loading conditions. In order to extend the applications of JP composites to structurally demanding applications, hybrid laminates made of jute-steel composites and jute with nanoclay-reinforced polyester have been investigated and the considerable enhancement of mechanical properties due to hybridization is shown. Furthermore, a comprehensive study has been conducted on the behavior of JP laminates for varying degrees of moisture content until saturation, and the efficacy of hybrid laminates in this context has been shown.

Miniature energy and chemical systems (MECS) are miniature thermal, fluid, and chemical devices in the mesoscale size range between a sugar cube and a human fist. MECS take advantage of improved rates of mass and heat transfer that have been observed at the microscale. There are many potential applications for MECS, including manportable cooling and decentralized chemical processing. However, this potential has not been realized due to limitations in microfabrication. MECS devices require: 1) the fabrication of complex geometries incorporating microscale features; and 2) the thermal, mechanical and chemical properties of engineering metals. This thesis centers on developing a process for producing high-aspect-ratio, MECS devices in stainless steel. In order to achieve this goal, laser ablation and diffusion bonding were employed in a metal microlamination (MML) process. The process involves stacking and bonding a series of laminates with low-aspect-ratio features to produce a composite device with high-aspect-ratio features (20:1). Laser ablation was used to form many laminates of 0.003" 302 stainless steel. These laminates were then joined via diffusion bonding. The process developed in this thesis is unique in that it: 1) permits the MECS designer greater freedom in specifying microchannel widths; and 2) has produced microscale features in excess of 20:1 aspect ratio. Microchannels and microfins in excess of 20:1 aspect ratio were fabricated in stainless steel using this method. Resultant microchannels were tested by flowing air through them at various flow rates and measuring the resulting pressure drop. Experimental results were compared with theoretical calculations and other technical literature. Findings suggest that the preliminary efforts to build a MECS device resulted in significant air blockage in the microchannel passageways. Sources of this blockage include bent fins, warpage and misalignment among others. Further process refinements are needed to prove the economic viability of this process.
Graduation date: 1998

碩士
國立中山大學
資訊管理學系研究所
99
Manufacturing Execution System (MES) is the major tool used to increase the effectiveness and efficiency of the operation management for the Steel Industry. Prior to implementing the MES, correctly estimating the MES Software Project Size is an important first stage and is a complex exercise. Several methods have been proposed to help in evaluating MES Software Project Size before implementation, such as function point analysis and fast function point analysis approaches. Among them, the fast function point analysis is a prominent approach. However, the detailed guideline for the use of it is lacking. Therefore, this study presents a methodology which provides these guidelines and uses it to estimate the MES Software Project Size in the Steel Industry. The research methodology is articulated using the design science research methodology. A usability evaluation is performed using three steel industry cases to demonstrate its applicability. With this enhanced approach, IT professionals or adopting organizations can more easily and systematically estimate the MES software project size.

Simultaneously achieving high-sensitivity and a large resonance frequency of micromachined accelerometers is difficult because of the inherent trade-off between the two. In this thesis, we present a mechanical displacement-amplifying technique that is amenable to micromachining to enhance sensitivity without compromising on the resonance frequency and cross-axis sensitivity. Depending on the requirements of sensitivity alone or sensitivity and resonance frequency, Displacement-amplifying Compliant Mechanisms (DaCMs) are designed using the selection map-based technique, which indicates the limits of what is possible for given specifications on size and microfabrication. In order to prove the benefits of a DaCM, we modified the designs of two very sensitive capacitive micromachined accelerometers from the literature by incorporating DaCMs and showed that, within the same footprint on the chip, the displacement sensitivity could be enhanced by more than 60% while the resonance frequency was also improved by more than 30%. As the focus of the thesis is to explore the integration of DaCMs into accelerometers, the analytical, computational, and practical aspects are discussed in detail. Both single and dual axis in-plane accelerometers are considered. The fabrication processes used are Silicon-on-Insulator Multi-user MEMS Processes (SOIMUMPs) and a customized Silicon-on-Insulator (SOI) based process. The fabricated accelerometers are packaged and brought to the product form. They were tested at the die level as well as in the packaged form. Under dynamic conditions, the measured amplification factor of the fabricated single-axis in-plane accelerometer was observed to be 11. The overall dimension of the accelerometer was 4.25 mm × 1.25 mm. The first in-plane natural frequency of the fabricated accelerometer was found to be 6.25 kHz. The voltage sensitivity of the packaged accelerometer with the DaCM measured 26.7 mV/g at 40 Hz with differential capacitance sensitivity of 3926 ppm/g around the base capacitance of 0.75 pF. The fabricated dual-axis accelerometer has a special configuration of twelve folded-beam suspension blocks that de-couple any displacements along the two in-plane orthogonal axes. The decoupling feature is retained even after adding the DaCMs along both the axes. The total device size was 8.6 mm × 8.6 mm. The device was also fabricated and packaged inside a ceramic flat-pin package using hybrid die-to-die wire-bonding. Die-level dynamic characterization showed that the average geometric advantage achieved using the DaCMs is 6.2 along both the in-plane axes. The measured axial voltage sensitivity of about 580 mV/g for both the axes was achieved with a cross-axial sensitivity of less than 2% and a natural frequency of 920 Hz. The static capacitance sensitivity was found to be 0.296 × 106 ppm/g with a base capacitance of 0.977 pF. Also presented in this work is a wide-band dual-axis accelerometer without an amplifying mechanism. Its first two in-plane modal frequencies measured 14.2 kHz. The measured sensitivity of the packaged accelerometer along both the axes of the device was found to be 62 mV/g at 200 Hz. Aiming at towards cost-effective accelerometers for small-volume markets, we also developed a single-axis and two dual-axis meso-scale spring-steel in-plane accelerometers equipped with Allegro A1395 linear Hall-effect sensors for sensing the displacement of the proof-mass. The single-axis in-plane meso-scale accelerometer also contains a DaCM. It is observed through simulation that the single-axis design with a DaCM is 39% more sensitive and has 41% more bandwidth compared to a single-axis design without a DaCM. The measured sensitivity of the fabricated single-axis spring-steel accelerometer with a DaCM was found to be 71.4 mV/g with a minimum resolvable acceleration of 14 milli-g. The unique features of the first generation of dual-axis accelerometers are that a rechargeable Li-ion battery adds to the proof-mass. It also contains a de-coupling mechanism that can decompose any planar acceleration into its axial components. The second generation of dual-axis accelerometers is more compact in size. All the mechanical elements of the accelerometers are made of EN J42/AISI 1080 spring steel foil machined using Wire-cut Electro-Discharge- Machining. The measured sensitivity of the first generation of dual-axis meso-scale accelerometers is 78 and 108 mV/g along the X and Y axes whereas the second generation device exhibits a sensitivity of 40 mV/g for both the axes. The thesis concludes that the sensitivity of a displacement-based sensor can be improved using a suitably designed DaCM without compromising the resonance frequency and hence the bandwidth. Furthermore, the work describing the development of meso-scale accelerometers also establishes spring steel as a viable material for meso-scale applications.

碩士
國立臺灣科技大學
機械工程系
97
The purpose of this study includes two parts, one is the Z-axis design of a meso-scale 3-axis milling machine, the other is the determination of the optimal micro-milling parameters using a high speed spindle for cutting the tool steel SKD61. Regarding the Z-axis design of a meso-scale 3-axis milling machine, it mainly includes a pagoda structure, the high speed air bearing spindle, two ultrasonic motors, a laser diffraction grating interferometer (LDGI), and a counter-balance system for the spindle. The optimal geometrical dimensions of the pagoda structure have been determined by the ANSYS software. The Taguchi’s experimental method has been applied to determine the optimal micro-milling parameters for the tool steel SKD61 using a micro-mill with the diameter of 0.5 mm. Based on the Taguchi’s L9 matrix experimental results and the analysis of variation (ANOVA), the optimal micro-milling parameters for milling the tool steel SKD61 were the combination of the stepover of 0.01 mm, the spindle speed of 60,000 rpm, the feed of 60 mm/min, and the depth of cut of 0.04 mm. The cutting forces measured by a micro-dynamometer were 0.278N, 0.327N, and 3.63N with respect to x-, y-, and z-axes, respectively, using the optimal micro-milling parameters. Appling the optimal micro-milling parameters to the surface finish of a lens model, the measured surface roughness of 0.06μm was obtainable.

The paper is concerned with the synchronic analysis of two ancient texts, i. e. 2 Kings 3, and the Mesha´s stele. Both of them mention an Israelite-Moabite conflict, and it is said they contain two different reports of the same event. The purpose of this thesis is to reconsider this assertion. Both texts were analyzed and their respective literary genres were determined. Then the texts were compared with regard to the aforementioned conflict. At the end of the paper the author concludes, it is neither possible to affirm with any certainty, that both texts reflect the same historical event, nor to disprove it.

The work deals with the historicity of King David, how muchcorresponds to the biblical story of David's ancient reality. Usingarchaeological survey of contemporary Israel and is run in the end of the 19th century. AD, the scientific community is divided into two main directions Maximalists conservative and liberal minimalists try to objectively assess the time of David the United Kingdom. The aim of my work is to capture the state of discussions withrepresentatives of scientists and scholars on the subject. The firstsection describes the basic concepts and contexts related to the topic with an introduction to the study and interpretation of thestudied biblical story of David. The second part is devoted to the interpretation of arguments and opinions of authors of publications,with perspectives on the historical authenticity of the biblical story of David. In conclusion, the thesis I try to summarize all the work using the main data connection, and data along with archeologicalfindings and express their personal opinion