A influência de variáveis metodológicas no valor da resistência de união e no padrão de fratura, por ensaio de microcisalhamento, foi verificada em dentina planificada de molares humanos e estudada em quatro diferentes experimentos, nos quais dois sistemas adesivos foram utilizados (Adper Single Bond 2 e XP Bond) e uma resina composta (Filtek Z250). Foram eles: Experimento 1- momento de fotoativação do adesivo: antes ou após o posicionamento das cânulas sobre o substrato dentinário; Experimento 2- tempo de armazenagem: 10min, 24 horas, 48 horas e 7 dias em água destilada a 37oC; Experimento 3- área de secção transversal dos corpos de prova: 0,44mm2, 0,82mm2, 1,98mm2 e 4,44mm2; Experimento 4- momento de fotoativação da resina / remoção da cânula para o ensaio. Os dados obtidos de resistência de união, em MPa, foram tratados por métodos de ANOVA. Os corpos de prova resultantes de todos os experimentos foram observados em microscopia eletrônica de varredura e analisados de forma qualitativa quanto ao modo de fratura. Houve diferença significativa no Experimento 1, sendo que os valores médios de resistência de união foram mais altos quando os adesivos foram fotoativados antes de posicionar as cânulas. Não houve diferença estatisticamente significante para as variáveis tempo de armazenagem e sistema adesivo (Experimento 2), e nem para as variáveis área de secção transversal e sistema adesivo estudadas (Experimento 3). Para o Experimento 4, houve diferença estatisticamente significante para a condição experimental resina fotoativada e remoção da cânula quando previamente realizada à adesão ao substrato e entre os adesivos. Em todos os experimentos o modo de fratura foi predominantemente adesivo/misto. Concluiu-se que algumas variáveis do método são fundamentais para sua padronização, pois com base nos resultados deste estudo elas influenciam os valores médios da resistência de união. / The effect of methodological variables on the microshear bond strength and fracture pattern was assessed in flat human molars dentin in four different experiments using two adhesive systems (Adper Single Bond 2 and XP Bond) and a composite resin (Filtek Z250). The experiments were: 1. Adhesive light activation moment prior or after mold positioning on dentin; 2. Storage period 10 min, 24h, 48h or 7 days in distilled water at 37oC; 3. Mold transversal section area 0.44mm2, 0.82mm2, 1.98mm2 and 4.44mm2; 4. Resin light activation moment with or without mold removal prior to testing. Mean data values (MPa) were subjected to ANOVAs methods. All fractured specimens were qualitatively analyzed in SEM to verify the fracture mode. Regarding Experiment 1 a significative difference was shown for the main factor Adhesive Light Activation Moment; higher bond strength values were achieved with adhesive system ligth activated before mold positioning. No significant differences were found for storage period or section area analyzed on Experiments 2 and 3, respectively. The main factor Resin Light Activation Moment presented differences when the resin composite was previously light activated and mold was removed prior to bonding the resin with the adhesive systems. In all experiments, mode of failure was predominantly adhesive/mixed. The conclusion is that some variables of the method are essential for its standardization, given that they influence the bond strength values.

The diploma thesis deals with the issue of risk management during order processing in the production company, named Slévárna Kuřim, a.s., which produces castings. The first part of the thesis presents the theoretical background. In the practical part, a specific company is introduced, an order processing is described, and all possible risks that may occur during order processing are identified. Their identification is done by using selected tools - the FMEA method and the Ishikawa diagram. The goal of the diploma thesis is to identify possible risks based on performed analysis and for the most serious risks propose measures that would minimize them.

The diploma thesis deals the risk management during order processing in the engineering company Balák stroje Tišnov Ltd., a producer of custom machines. The aim of the diploma theses is to identify and evaluate the risks that may arise during the order processing. A partial aim is to propose a list of recommendations to minimize the most serious risks. The thesis is divided into three parts, where the first part of the thesis is focused on theoretical basis. The second part – analytical part contains the introduction of the company, the research part, description of the order processing and risks identification and evaluation, using selected methods – FMEA and Ishikawa diagram. The last part contains proposals for mitigating the most serious risks.

Bridge edge beam system is an increasing concern in Sweden. Because it is the mostvisible part of the structure which is subjected to harsh weather. The edge beamcontributes to the stiffness of overhang slab and helps to distribute the concentratedload. The design of edge beam is not only affected by the structural members, but it isalso affected by non-structural members.The aim of the thesis is to investigate the influence of edge beam on the structuralbehavior of reinforced concrete overhang slab. A three-dimensional (3D) non-linearfinite element model is developed by using the commercial software ABAQUS version6.1.14. The load displacement curves and failure modes were observed. The bendingmoment and shear capacity of the cantilever slab is studied.The validated model from non-linear analysis of reinforced concrete slab gives morestiffer result and leads to the high value of load capacity when comparing with theexperimental test. The presence of the edge beam in the overhang slab of length 2.4 mslightly increases the load capacity and shows ductile behavior due to the self-weightof the edge beam. The non-linear FE-analysis of overhang slab of length 10 m leads tomuch higher load capacity and gives stiffer response as compare to the overhang slabof 2.4 m. The presence of the edge beam in the overhang slab of length 10 m giveshigher load capacity and shows stiffer response when comparing with the overhangslab of length 10 m. This might be due to the self-weight of the edge beam and theoverhang slab is restrained at the right side of the slab.

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The objectives of the thesis were to find the mechanisms that govern compression failures in paperboard and to find the link between manufacturing process and paperboard properties. The thesis also investigates two different test methods and evaluates how suitable they are for paperboard grades. The materials are several commercial board grades and a set of hand-formed dynamic sheets that are made to mimic the construction of commercial paperboard. The method consists of mounting a stereomicroscope on a short-span compression tester and recording the compression failure on video, long-span compression testing and standard properties testing. The observed failure modes of paperboard under compression were classified into four categories depending on the appearance of the failures. Initiation of failure takes place where the structure is weakest and fiber buckling happens after the initiation, which consists of breaking of fiber-fiber bonds or fiber wall delamination. The compression strength is correlated to density and operations and raw materials that increase the density also increases the compression strength. Short-span compression and Long-span compression are not suitable for testing all kinds of papers; the clamps in short-span give bulky specimens an initial geometrical shape that can affect the given value of compression strength. Long-span compression is only suitable for a limited range of papers, one problem with too thin papers are low wavelength buckling.

This dissertation is to obtain an overall understanding of the crack path selection in adhesively bonded joints. Using Dow Chemical epoxy resin DER 331® with various levels of rubber concentration as an adhesive, and aluminum 6061-T6 alloy with different surface pretreatments as the adherends, both symmetric and asymmetric double cantilever beam (DCB) specimens are prepared and tested under mixed mode fracture conditions in this study. Post-failure analyses conducted on the failure surfaces indicate that the failure tends to be more interfacial as the mode II component in the fracture increases whereas more advanced surface preparation techniques can prevent failure at the interface. Through mechanically stretching the DCB specimens uniaxially until the adherends are plastically deformed, various levels of T-stress are achieved in the specimens. Test results of the specimens with various T-stresses demonstrate that the directional stability of cracks in adhesive bonds depends on the T-stress level. Cracks tend to be directionally stable when the T-stress is compressive whereas directionally unstable when the T-stress is tensile. However, the direction of crack propagation is mostly stabilized when more than 3% mode II fracture component is present in the loading regardless of the T-stress levels in the specimens. Since the fracture sequences in adhesive bonds are closely related to the energy balance in the system, an energy balance model is developed to predict the directional stability of cracks and the results are consistent with the experimental observations. Using the finite element method, the T-stress is shown to be closely related to the specimen geometry, indicating a specimen geometry dependence of the directional stability of cracks. This prediction is verified through testing DCB specimens with various adherend and adhesives thicknesses. By testing the specimens under both quasi-static and low-speed impact conditions, and using a high-speed camera to monitor the fracture sequence, the influences of the debond rate on the locus of failure and the directional stability of cracks are investigated. Post-failure analyses suggest that the failure tends to be more interfacial when the debond rate is low and tends to be more cohesive when the debond rate is high. However, this rate dependence of the locus of failure is greatly reduced when more advanced surface preparation techniques are used in preparing the specimens. The post-failure analyses also reveal that cracks tend to be more directionally unstable as the debond rate increases. Finally, employing interface mechanics and extending the criteria for the direction of crack propagation to adhesively bonded joints, the crack trajectories for directionally unstable cracks are predicted and the results are consistent with the overall features of the crack paths observed experimentally. / Ph. D.

Miniaturizing circuit size and increasing power density are the latest trends in modern power electronics development. In order to meet the requirements of higher frequency and higher power density in power electronics applications, planar interconnections are utilized to achieve a higher integration level. Power switching devices, passive power components, and EMI (Electromagnetic Interference) filters can all be integrated into planar power modules by using planar metallization, which is a technology involving electrical, mechanical, material, and thermal issues. By processing high dielectric materials, magnetic materials, or silicon chips using compatible manufacturing procedures, and by carefully designing structures and interconnections, we can realize the conventional discrete inductors, capacitors, and switch circuits with planar modules. Compared with conventional discrete components, the integrated planar modules have several advantages including lower profiles, better form factors, and less labor-intensive processing steps. In addition, planar interconnections reduce the wire bond inductive and resistive parasitic parameters, especially for high frequency applications. However, planar integration technology is a packaging approach with a large contact area between different materials. This may result in unknown failure mechanisms in power applications. Extensive research has already been done to study the performance, processing, and reliability of the planar interconnects in thin film structures. The thickness of the thin films used in integrated circuits (IC) or microelectronics applications ranges from the magnitude of nanometers to that of micrometers. In this work, we are interested in adopting planar interconnections to Integrated Power Electronics Modules (IPEM). In Integrated Power Electronics Modules (IPEMs), copper traces, especially bus traces, need to conduct current ranging from a few amps to tens of amps. One of the major differences between IC and IPEM is that the metal layer in IPEMs (normally >75µm) is much thicker than that of the thin films in IC (normally <1µm). The other major difference, which is also a feature of IPEM, is that the planar metallization is deposited on different brittle substrates. In active IPEM, switching devices are in a bare die form with no encapsulation. The copper deposition is on top of the silicon chips and the insulation polyimide layer. One of the key elements for passive IPEM and the EMI IPEM is the integrated inductor-capacitor (LC) module, which realizes equivalent inductors and capacitors in one single module. The deposition processes for silicon substrates and ceramic substrates are compatible and both the silicon and ceramic materials are brittle. Under high current and high temperature conditions, these copper depositions on brittle materials will cause detrimental failure spots. Over the last few years, the design, manufacture, optimization, and testing of the IPEMs has been developed and well documented. Up to this time , the research on failure mechanisms of conventional integrated power modules has led to the understanding of failures centered on wire bond or solder layer. However, investigation on the reliability and failure modes of IPEM is lacking, particularly that which uses metallization on brittle substrates for high current operations. In this study, we conduct experiments to measure and calculate the residual stresses induced during the process. We also, theoretically model and simulate the thermo-mechanical stresses caused by the mismatch of thermal expansion coefficients between different materials in the integrated power modules. In order to verify the simulation results, the integrated power modules are manufactured and subjected to the lifetime tests, in which both power cycling and temperature cycling tests are carried out. The failure mode analysis indicates that there are different failure modes for copper films under tensile or compressive stresses. The failure detection process verifies that delamination and silicon cracks happen to copper films due to compressive and tensile stresses respectively. This study confirms that the high stresses between the metallization and the silicon are the failure drivers in integrated power electronics modules.. We also discuss the driving forces behind several different failure modes. Further understanding of thesefailure mechanisms enables the failure modes to be engineered for safer electrical operation of IPEM modules and helps to enhance the reliability of system-level operation. It is also the basis to improve the design and to optimize the process parameters so that IPEM modules can have a high resistance to recognized failures. / Ph. D.

Examensarbetet har genomförts vid Högskolan i Skövde i samverkan med Nobia AB. Målet var att implementera ekodesignmetoder i Nobias befintliga designprocess och att genomföra en fallstudie på en kökslucka. Fallstudien genomfördes för att verifiera ekodesignprocessen och för att föreslå ett lämpligt material till en kökslucka. Under litteraturstudien undersöktes begrepp såsom hållbar utveckling, ekodesign och livscykel. Intervjuer genomfördes för att undersöka Nobias designprocess och för att identifiera aktiviteterna i varje fas i processen. Faserna var Idégenerering, Konceptutveckling, Produktutveckling och Industrialisering. Flera alternativa ekodesignmetoder studerades för att undersöka om de var lämpliga att implementera i Nobias befintliga designprocess, bland annat Statusanalys och olika Checklistor. De förväntade egenskaperna för ekodesignprocessen sammanställdes i en kravspecifikation. Ekodesignmetoderna som implementerades i Nobias befintliga designprocess resulterade i en ekodesignprocess, som bestod av Ekostrategihjul, Philips five fast, Jämförelsematris, Ekodesignportfolio, Miljöriskanalys och Scorecard. Fallstudien inleddes med skapandet av en kravspecifikation beträffande materialets förväntade egenskaper. De mest intressanta materialen var Medium Density Fibreboard, bambu och gran. Genom en analys av olika material ansågs gran vara det bästa materialet, eftersom det medförde minst utsläpp vid transport, tillgången är god samt är lokalt producerat. Det framkom att tillämpningen av ekodesign inom produktutveckling medför många fördelar, som till exempel en trivsam arbetsplats, motiverade medarbetare och en mer hållbar designprocess. En hållbar designprocess bidrar till att utveckla hållbara produkter, vilket bidrar till en bättre miljö. / The bachelor project has been carried out at the University of Skövde in collaboration with Nobia AB. The purpose of the project was to implement eco-design methods into the company’s existing design process and to accomplish a case study of a cabinet door. The purpose of the case study was to verify the proposed eco-design process and suggest a material for a cabinet door. Sustainable development, eco-design and lifecycle were studied during the literature study. Interviews were carried out to study the design process at Nobia and to identify the different activities in every phase of the process. The phases were Idea Generation, Concept Development, Product Development and Industrialization. Several eco-design methods were studied to assess their potential to be implemented into Nobia’s existing design process, for example Status Analysis and various Checklists. The expected characteristics of the eco-design process were compiled into a requirement specification. The methods which were implemented into Nobia’s existing design process resulted in an Eco-design process which consisted of Ekostrategihjul, Philips five fast, Jämförelsematris, Eco-design portfolio, Environmental Failure Mode and Effect Analysis and Scorecard. The case study was initiated by compiling a requirement specification. The most promising materials were Medium Density Fibreboard, bamboo and fir. Through analysis of various materials fir was considered as the best material because of low levels of pollution during transportation, good access to the raw material and it is also locally manufactured. The results show that the use of eco-design within product development entails many advantages, such as, a pleasant place of work, motivated staff, and a more sustainable design process. A sustainable design process will contribute to the development of sustainable products, which entails a better environment.

O presente trabalho apresenta um modelo de aplicação de ferramentas de projeto integradas ao longo das fases de desenvolvimento de produto, neste caso, aplicadas na melhoria do produto suporte para fixação de cilindro de gás natural veicular. O foco do trabalho é apresentar a integração de ferramentas nas fases de Projeto Informacional, Projeto Conceitual e Projeto Detalhado do Processo de Desenvolvimento de Produtos. Entende-se por integração a escolha de ferramentas que permitam conduzir o fluxo de informação ao longo das fases de desenvolvimento de produtos, de tal forma que a informação de saída de uma ferramenta seja a informação de entrada da ferramenta subseqüente. As ferramentas integradas a partir da fase de Projeto Informacional foram a Pesquisas de Mercado Qualitativa e Quantitativa, com a finalidade de identificar as demandas dos clientes. As demandas dos clientes foram os dados de entrada da Matriz da Qualidade (Quality Function Deployment - QFD), resultando nos requisitos do produto e suas respectivas especificações-meta. A partir dos requisitos do produto, diferentes conceitos (configurações) foram gerados, apoiados pela Matriz Morfológica no Projeto Conceitual. Na seqüência utilizou-se a ferramenta de Projeto de Experimentos (Design of Experiments - DOE) para avaliar a estimativa de preço frente às possíveis configurações do produto. Com a Matriz de Pugh, alternativas de conceito de produto foram avaliadas possibilitando a escolha do melhor conceito de produto. No Projeto Detalhado, foi aplicada ferramenta de Análise dos Modos de Falha e seus Efeitos (Failure Mode and Effects Analysis - FMEA), utilizado de forma integrada com o QFD, para identificar as falhas atuais e potenciais e seus efeitos em sistemas e processo. Em função das demandas identificadas, foram definidas e implementadas melhorias no produto. Observou-se a adequabilidade destas ferramentas de projeto para aplicação de forma integrada, garantindo um fluxo contínuo de informações rastreáveis e que tendem a levar à uma reduzida chance de perdas ao longo do processo. / There are few examples in literature about the integration of project tools along the product development phases. The main research objective in thesis is to integrate some tools that facilitate the information flow along the product development phases, more specifically in Informational Project, Conceptual Project and Detailed Project phases. The product improvement “support for Vehicular Natural Gas” was the object of study in thesis. The main idea is that the information output from one tool is the input information of the subsequent tool. Starting from the Informational Project phase it was performed qualitative and quantitative market researches with the purpose of identifying the customers' demands for the studied product. The customers’ demands were the entrance data of the QFD (Quality Function Deployment) tool resulting in the product requirements and their respective specifications-goal. In Concept Project the product requirements were converted in functions and further different concepts were generated through the Morphologic Analysis. In the sequence, it was used the DOE (Design for experiments) tool to evaluate the estimate price to the possible products' configurations. The Pugh Matrix tool was used for concepts evaluation and choice. The FMEA (Failure Mode and Effects Analysis) tool integrated with QFD was useful for current and potential failures identification and impact analysis in the system and process. With the application of these five tools the users’ demands were identified and improvements to the product were performed. The chosen tools proved to be adequate for integration, assuring that a continuous trackable information flow was attained with presumable reduced information loss, along the Product Development Process phases.