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Mobbning i arbetslivet : en dokumentanalysZebili, Dimka, Aram Aslan, Jakob January 2014 (has links)
Mobbning i arbetslivet är ett dolt problem som alltid funnits på arbetsplatser i Sverige. Vuxenmobbning handlar om psykiskt våld och upprepade kränkningar som skadar människor och leder till utfrysning, utslagning och isolering. Syftet med studien är att öka förståelsen och kunskapen kring mobbningsproblematiken på arbetsplatsen och dess konsekvenser. Syftet är också att ta reda på vilka rättsliga möjligheter och begränsningar det finns att vidta, samt vilka förebyggande strategier som forskning och utredningar föreslår. Materialet består av fyra domstolsbeslut kring mobbning i arbetslivet. Syftet uppnås med hjälp av en dokumentanalys av materialet. Resultaten analyseras med hjälp av två teoretiska modeller: förloppsmodellen och rollmodellen samt teorier om stigma och stämpling. I uppsatsen sammanställs empirin utifrån fyra teman: konflikter, syndabockarna, krisen och utslagningen. Studiens huvudresultat är att destruktiv ledarskap och missköta konflikter skapar förutsättningar för mobbning i arbetslivet och resulterar i att människor stigmatiseras, stämplas som avvikare och exkluderas från samhället. Avslutningsvis görs förslag till vidare studier utifrån funderingar kring huruvida lagändringar skulle kunna påverka hanteringen av grundproblemet positivt vad gäller mobbning i arbetslivet. / Bullying in the life of work is a concealed issue that always has existed in Swedish workplaces. Adult bullying is about mental violence and repeated violations that harm people and often leads to ostracism, exclusion and isolation. The aim of this study is to increase understanding and knowledge about the bullying issue in workplaces and its consequences. The aim is also to find out what legal possibilities and limits there are to take and what preventative strategies that research and investigations suggests. In order to find out about this we have based our study on four court decisions dealing with bullying in the workplace. In addition, official documents, newspaper articles, laws and documents issued by authorities and other organizations that publish articles on the Internet are also used in this study. The aim is achieved by using a document analysis of data. It is compiled on empirical data based on four themes: conflicts, scapegoats, crisis and exclusion. The results are analyzed by using two theoretical models: progress model and role model, and also theories about stigma and stamping are being used. The basic finding is that the destructive leadership and mismanage conflict create conditions for bullying in the workplace and results in people stigmatized, branded as outliers and excluded from society. Finally made suggestions for further studies based on concerns about whether legislative changes could affect the handling of the basic problem positively in terms of bullying in the workplace.
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Inkjet-assisted printing of encapsulated polymer/biopolymer arraysSuntivich, Rattanon 27 August 2014 (has links)
The goal of the proposed study is to understand the morphology, physical, and responsive properties of synthetic polymer and biopolymer layer-by-layer (LbL) arrays using the inkjet printing and stamping technique, in order to develop patterned encapsulated thin films for controlled release and biosensor applications. In this study, we propose facile fabrication processes of hydrogen-bonded and electrostatic LbL microscopic dot arrays with encapsulated target organic and cell compounds. We study encapsulation with the controllable release and diffusion properties ofpoly(vinylpyrrolidone) (PVPON), poly(methacrylic acid) (PMAA), silk-polylysine, silk-polyglutamic acid, pure silk films, and E-coli cells from the multi-printing process. Specifically, we investigate the effect of thickness, the number of bilayers, and the hydrophobicity of substrates on the properties of inkjet/stamping multilayer films such as structural stability, responsiveness, encapsulation efficiency, and biosensing properties.
We suggest that a more thorough understanding of the LbL assembly using inkjet printing and stamping techniques can lead to the development of encapsulation technology with no limitations on either the concentration of loading, or the chemical and physical properties of the encapsulated materials. In addition, this study offers new encapsulation concepts with simple, cost effective, highly scalable, living cell-friendly, and controllable patterning properties.
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High Strain Rate Behaviour of Hot Formed Boron Steel with Tailored PropertiesBardelcik, Alexander January 2012 (has links)
In an automotive crash event, hot stamped, die quenched martensitic structural components have been shown to provide excellent intrusion resistance. These alloys exhibit only limited ductility, however, which may limit the overall impact performance of the component. The introduction of lower strength and more ductile “tailored” properties within some regions of a hot stamped component has the potential to improve impact performance. One approach being applied to achieving such tailored properties is through locally controlling the cooling rate within the stamping die. The primary motivation for the current work is to understand the role of cooling rate on the as-quenched mechanical response of tailored hot stampings, which has required characterization of the high strain rate mechanical behaviour of tailored hot stamped boron steel.
The effect of cooling rate and resulting microstructure on the as-quenched mechanical behavior of USIBOR® 1500P boron steel at strain rates between 10-3 and 103 s-1 was investigated. Specimens quenched at rates above the critical cooling rate (~27 °C/s) exhibited a fully martensitic microstructure with a UTS of ~1,450 MPa. Sub-critical cooling rates, in the range 14°C/s to 50 °C/s, resulted in as-quenched microstructures ranging between bainitic to martensitic, respectively. Tension tests revealed that predominantly bainitic material conditions (14 °C/s cooling rate) exhibited a lower UTS of 816 MPa compared to 1,447 MPa for the fully martensitic material condition (50 °C/s cooling rate) with a corresponding increase in elongation from 0.10 to 0.15 for the bainitic condition. The reduction in area was 70% for the bainitic material condition and 58% for the martensitic material conditions which implied that a tailored region consisting of bainite may be a desirable candidate for implementation within a hot stamped component. The strain rate sensitivity was shown to be moderate for all of the as-quenched material conditions and the measured flow stress curves were used to develop a strain rate sensitive constitutive model, the “Tailored Crash Model (TCM)”. The TCM accurately reproduced the measured flow stress curves as a function of effective plastic strain, strain rate and Vickers hardness (or area fraction of martensite and bainite).
The effect of deformation during quenching and the associated shift in the CCT diagram on the subsequent constitutive response was also examined for this material. Specimens were simultaneously quenched and deformed at various cooling rates to achieve a range of as-quenched microstructures that included ferrite in addition to martensite and bainite. Tensile tests conducted on these specimens at strain rates ranging from 0.003 s-1 to ~80 s-1 revealed that the presence of ferrite resulted in an increase in uniform elongation and n-value which increased overall energy absorption for a given hardness level. The strain rate sensitivity was shown to be moderate for all of the as-quenched material conditions and the TCM constitutive model was extended to account for the presence of ferrite. This extended constitutive model, the “Tailored Crash Model II (TCM II)”, has been shown to predict flow stress as a function of effective plastic strain, strain rate and area fraction of martensite, bainite and ferrite.
As a validation exercise, uniaxial tension test simulations of specimens extracted from the transition zone of a hot stamped lab-scale B-pillar with tailored properties [1] were performed. The measured hardness distribution along the gauge length of the tensile specimens was used as input for the TCM constitutive model to define the element constitutive response used in the finite element (FE) models. The measured stress versus strain response and strain distribution during loading (measured using digital image correlation) was in excellent agreement with the FE models and thus validated the TCM constitutive model developed in this work. Validation of the TCM II version of the model is left for future work.
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Determination of process parameters for stamping and sheet hydroforming of sheet metal parts using finite element methodPalaniswamy, Hariharasudhan, January 2007 (has links)
Thesis (Ph. D.)--Ohio State University, 2007. / Title from first page of PDF file. Includes bibliographical references (p. 265-278).
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Prediction and elimination of galling in forming galvanized advanced high strength steels (AHSS)Kim, Hyunok, January 2008 (has links)
Thesis (Ph. D.)--Ohio State University, 2008. / Title from first page of PDF file. Includes bibliographical references (p. 152-158).
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Análise da estampagem de chapas metálicas utilizando elementos finitosCosta, Ailton Rodrigues da [UNESP] 29 October 2003 (has links) (PDF)
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costa_ar_me_guara.pdf: 5961814 bytes, checksum: b7f2d200f9efde1986c3d1aed991c288 (MD5) / Os processos de estampagem em chapas metálicas destacam-se entre os processos de conformação plástica de metais por possibilitarem a obtenção de peças com formatos diversos e boas propriedades mecânicas. A simulação de processos de fabricação é atualmente uma realidade possibilitando uma melhor compreensão do comportamento dos metais e de processos assim como os avanços na área computacional que permitem desenvolver e aperfeiçoar os programas de simulação. Neste trabalho é apresentada a simulação do processo de embutimento de uma caixa quadrada utilizando o programa comercial de elementos finitos ANSYS, onde foram introduzidas as condições e propriedades reais tanto do processo quanto do material estudado. Nas simulações numéricas são avaliados dois parâmetros do processo de embutimento. O primeiro, é analisada a variação da força máxima de embutimento, até a profundidade limite de estampagem. O segundo, as deformações na espessura do material, é verificada a variação da espessura da chapa devido ao processo de estampagem. Os resultados numéricos são confrontados com os resultados experimentais com o objetivo de validar as simulações. / The stamping processes in metallic foils stand out among the processes of forming metals for they make possible the obtaining of pieces with several shapes and good mechanical properties. The simulation of production processes is now a reality to permit a better understanding of the behavior of the metals and of processes as well as the progresses in the computational area that allow to develop and to improve the simulation programs. In this work the simulation of the process of deep-drawing of a square box is presented using the commercial program of finite elements ANSYS, where the conditions and real properties were introduced as much the process of the studied material. In the numeric simulations it is presented two parameters of the deepdrawing process. The first, the variation of the maximum force deep-drawing is analyzed, until the depth stamping limit. The second, the deformations in the thickness of the material, the variation of the thickness of the foil is verified due to the stamping process. The numeric results are compared to the experimental results with the objective of validating the simulations.
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Caractérisation avancée des matériaux en vue de la prédiction de la localisation sur des tôles minces / Advanced characterization of materials for predicting the location of thin metal sheetsKsiksi, Nesrine 09 December 2016 (has links)
La détermination des conditions de chargements limites qui produisent une localisation du matériau est toujours un enjeu important, notamment lorsqu'il s'agit d'optimiser les dimensions d'outillage lors d'opérations durant lesquelles le matériau est fortement sollicité. Différents travaux récents ont montré que l'hétérogénéité structurale intrinsèque à tout matériau métallique joue un rôle important dans les différents stades de déformation. Le rôle des hétérogénéités sur la localisation n'est cependant pas abordé. L'objectif de cette thèse est donc de déterminer si l'hétérogénéité structurale des matériaux a un impact sur la localisation des matériaux ductiles. Une action corollaire est alors de valider le recours à des modèles qui intègre cette hétérogénéité pour obtenir des meilleurs résultats.Cette étude comprend deux volets. Le premier volet expérimental a pour objectif de constituer un référentiel expérimental qui met en évidence l'impact du facteur hétérogénéité sur la localisation. Différentes éprouvettes de titane ont été préparées de façon à obtenir différents degrés d'hétérogénéités. Deux paramètres ont été utilisés à cette fin : l'épaisseur et la structure cristalline. Le titane permet en effet de disposer de matériaux à structure hexagonale et cubique centrée qui présentent des possibilités d'accommodation plastique très différentes. Des essais de traction et d'expansion ont ainsi été pratiqués sur des éprouvettes de titane de tôle fine et épaisse dans les structures α et β du titane de nuance T40. Trois tôles différentes : Tiα(tôle fine); Tiα(tôle épaisse) et Tiα+β(tôle épaisse) ont été utilisées lors des essais. Pour obtenir les tôles Tiα+β un traitement thermique a été optimisé et l’analyse des tôles a été effectuée à l’aide de plusieurs techniques comme le MEB, les rayons X et l'ATD. Un second volet numérique s'est appuyé sur deux modèles pour réaliser la simulation des essais expérimentaux. Un premier modèle de type phénoménologique "classique", sans facteur d'hétérogénéité a tout d'abord été utilisé pour simuler le comportement idéal d'un matériau homogène. Dans un second temps, le recours à un modèle qui intègre une dimension physique, l'hétérogénéité, a montré que cette dernière a une incidence notable et permet d'améliorer la prédiction du phénomène de localisation. / The determination of limit loading conditions producing the localization in the material is always an important subject, notably as it is about the optimization of tool dimension during operations during which material is strongly solicited. Different recent works have shown that intrinsic structural heterogeneity inside any metallic material plays an important role in the different stages of deformation. However, the role of heterogeneities in localization is not addressed.The objective of this PhD thesis is therefore to determine if the structural heterogeneity of materials has an impact on the localization of ductile materials. A corollary action is then to validate the use of models which integrate this heterogeneity for best results.This study has two parts.The first experimental part has for objective to constitute an experimental base which highlights the impact of the heterogeneity factor on localization. Different titanium specimens were prepared so as to obtain different degrees of heterogeneities.Two parameters were used for this purpose: thickness and crystal structure. Titanium makes it possible to have materials with hexagonal structure and cubic centered that present possibilities of very different plastic accommodation.Tensile and equi-axial tests have thus been carried out on titanium specimens for thin and thick metal sheet in the structures α and β for T40 grade Titanium.Three different sheets Tiα(thin); Tiα(thick) et Tiα+β(thick) were used during the tests. To obtain the sheets Tiα+β, a heat treatment has been optimized and sheets analysis was done using several techniques such as SEM, X Rays and ATD. A second numerical part was based on two models to realize numerical simulation of the experimental tests. A first classical phenomenological model without heterogeneity factor was firstly used to simulate the ideal behavior of a homogeneous material. In a second time, the use of a model that incorporates a physical dimension that is to say the heterogeneity, has shown that this latter has a significant impact and makes it possible to improve the prediction of localization phenomenon.
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FORMAS NOVAS, TEMAS ANTIGOS: CONECTANDO HISTÓRIA E PATRIMÔNIO NA CRIAÇÃO DE PADRÕES GRÁFICOS PARA DIVULGAR SANTA MARIA / NEW WAYS, OLD THEMES: CONNECTING HISTORY AND HERITAGE TO CREATE GRAPHIC PATTERNS TO PROMOTE SANTA MARIAMorales, Pedro Ceccim 28 February 2012 (has links)
Preservation of Architectural Heritage listed on the Brazilian Register of Historic Sites an issue widely discussed nowadays presupposes questions which are not always addressed by professionals involved in the preservation field. One of these questions is raising funds for maintenance of such historic sites as well as approaching these constructions and their respective communities, since it is possible to see in the cities routine the existing failures in the compliance with preservation regulations which cannot, by themselves, ensure preservation of these elements responsible for materializing memories and experience obtained throughout History. Nevertheless, the lack of preservation awareness, widely spread in our society, also shows the population lack of knowledge about History and the importance of these urban elements which not only illustrate the past of cities, but also define the identity of citizens living in these towns. These cultural definitions of the subjects may be reinforced, redefined or even produced by the different media languages that appear and/ or are reinvented according to progress coming from research, technology advances, and new possibilities of interaction, among others. Accordingly, this paper aims at promoting the set of historic buildings under preservation laws in Santa Maria through the stamping technique, inspired by the formal features of these buildings architecture. Thus, identity bonds between the city s population and its historic buildings are strengthened. In addition, an income source is proposed for maintenance and preservation of these sites. As it is common knowledge, we only value what we know. / A preservação do Patrimônio Arquitetônico Tombado, pertencente às cidades brasileiras - assunto tão debatido na atualidade -, pressupõe questionamentos que nem sempre são abordados pelos profissionais envolvidos na área de preservação. Um deles é a obtenção de verba para a manutenção dos bens tombados, bem como a aproximação entre essas construções e suas respectivas comunidades, já que é possível averiguar no cotidiano das urbes, as falhas existentes no cumprimento das leis de tombo que não conseguem assegurar, por si só, a garantia de preservação desses elementos responsáveis por materializar as memórias e vivências obtidas no decorrer da história. Não obstante, a falta de uma consciência preservacionista, amplamente disseminada na sociedade, também demonstra a falta de conhecimento das populações acerca da história e da importância desses elementos urbanos que ilustram não só o passado das cidades, mas também definem a identidade dos indivíduos que nelas habitam. Essas definições culturais sobre os sujeitos podem ser reforçadas, refeitas ou até mesmo fabricadas pelas diferentes linguagens midiáticas que surgem e ou se reinventam ao sabor dos progressos obtidos através de pesquisas, avanços tecnológicos, novas possibilidades de interação, entre outros. Nesse sentido, o presente trabalho surge com o intuito de divulgar o conjunto de prédios históricos tombados de Santa Maria, através da técnica de estamparia, inspirada nas características formais da arquitetura desses prédios, buscando, assim, reforçar os laços identitários entre a população da cidade de Santa Maria e seus prédios históricos, bem como propor uma fonte de renda para a manutenção e preservação desses bens, pois, como é de conhecimento popular, só valorizamos aquilo que conhecemos. .
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Análise da estampagem de chapas metálicas utilizando elementos finitos /Costa, Ailton Rodrigues da. January 2003 (has links)
Orientador : Fernando de Azevedo Silva / Banca: Gustavo Aristides Santana Martinez / Banca: Angelo Caporali Filho / Resumo: Os processos de estampagem em chapas metálicas destacam-se entre os processos de conformação plástica de metais por possibilitarem a obtenção de peças com formatos diversos e boas propriedades mecânicas. A simulação de processos de fabricação é atualmente uma realidade possibilitando uma melhor compreensão do comportamento dos metais e de processos assim como os avanços na área computacional que permitem desenvolver e aperfeiçoar os programas de simulação. Neste trabalho é apresentada a simulação do processo de embutimento de uma caixa quadrada utilizando o programa comercial de elementos finitos ANSYS, onde foram introduzidas as condições e propriedades reais tanto do processo quanto do material estudado. Nas simulações numéricas são avaliados dois parâmetros do processo de embutimento. O primeiro, é analisada a variação da força máxima de embutimento, até a profundidade limite de estampagem. O segundo, as deformações na espessura do material, é verificada a variação da espessura da chapa devido ao processo de estampagem. Os resultados numéricos são confrontados com os resultados experimentais com o objetivo de validar as simulações. / Abstract: The stamping processes in metallic foils stand out among the processes of forming metals for they make possible the obtaining of pieces with several shapes and good mechanical properties. The simulation of production processes is now a reality to permit a better understanding of the behavior of the metals and of processes as well as the progresses in the computational area that allow to develop and to improve the simulation programs. In this work the simulation of the process of deep-drawing of a square box is presented using the commercial program of finite elements ANSYS, where the conditions and real properties were introduced as much the process of the studied material. In the numeric simulations it is presented two parameters of the deepdrawing process. The first, the variation of the maximum force deep-drawing is analyzed, until the depth stamping limit. The second, the deformations in the thickness of the material, the variation of the thickness of the foil is verified due to the stamping process. The numeric results are compared to the experimental results with the objective of validating the simulations. / Mestre
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Estudo da análise de fadiga pelo MEF considerando os efeitos da estampagem / Study of fatigue analysis by FEM considering the metal stamping effectsAguado, Clodoaldo Garcia 18 August 2018 (has links)
Orientador: Alfredo Rocha de Faria / Dissertação (mestrado profissional) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecânica / Made available in DSpace on 2018-08-18T21:18:25Z (GMT). No. of bitstreams: 1
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Previous issue date: 2011 / Resumo: As simulações dentro do ambiente de projeto devem prever a utilização de novas variáveis, especialmente de processos, de forma a aumentar a proximidade entre os modelos virtual e real e, com isso, aumentar a precisão das simulações. O objetivo deste trabalho foi o de estudar um modelo pelo Método dos Elementos Finitos que incluísse os efeitos da variação de espessura provenientes do processo de estampagem para a análise de vida em fadiga de um componente do sistema de exaustão automotivo. Primeiramente foi realizada a simulação do processo de estampagem, onde foi possível identificar as mudanças de espessura na geometria do componente estudado. O resultado dessa simulação foi transportado para a malha de elementos finitos, de forma que as análises posteriores, estrutural e de fadiga, considerassem os efeitos da redução e aumento da espessura local. Como base de comparação, as mesmas análises foram realizadas para a condição de espessura constante, tradicionalmente adotada durante a fase de projeto. Utilizando o modelo de Wöhler-Goodman-Miner para o cálculo do Dano acumulado e comparando com dados experimentais aquisitados em simulador veicular, os resultados cálculo de fadiga demonstraram que ambas as condições de espessura atingem vida infinita. Entretanto, após a seleção e análise de algumas regiões consideradas críticas nas simulações precedentes (estampagem e estrutural), pôde-se notar que na maior parte das regiões os valores de dano acumulado eram inferiores para a condição de espessura constante. Já a condição de espessura variável se aproximou mais ao resultado medido. Pôde-se concluir com os resultados que a variação de espessura, como efeito do processo de estampagem, desempenha um papel importante na vida do componente estudado, indicando que a utilização dos dados de processo auxilia na aproximação entre os resultados do cálculo de vida e a condição real / Abstract: The simulations within the Product Development environment must give the chance to use new variables, particularly from processes, in order to improve the correlation between the virtual and real models, and thus enhance the accuracy of the simulations. The objective of this work was to study a model by the finite element method (FEM) that includes the effects of thickness variation from stamping process for the fatigue life prediction in an automotive exhaust system component. Firstly it was carried out a simulation of the stamping process, where it was possible to identify the thickness distribution all along the geometry of selected component. Then, the result of this simulation was transported to the finite element mesh, so that further analyses, structural and fatigue, could consider the effects of reduction and increasing in local thickness. As a basis for comparison, the same analyses were performed for the homogeneous geometry (uniform thickness), which are typically taken during the design phase. Using the model proposed by Wöhler-Goodman-Miner to calculate the accumulated damage and comparing with real data acquisited from a vehicle, the calculation results of fatigue showed that both conditions (equal and unequal thickness) reached infinite life. However, after the selection and analysis of some critical regions in the previous simulations (stamping and structural), it might be noted that, in most regions, the values of accumulated damage were lower for the uniform thickness condition. Besides, for the unequal thickness condition, the results got closer to those measured in vehicle. With these results, it could be demonstrated that the unequal thickness, as a process variable, plays an important role in the component life, indicating that the use of process data helps in bringing together the results from fatigue calculation and real condition / Mestrado / Manufatura / Mestre em Engenharia Automobilistica
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