La sécurité du piéton est un problème de santé publique, qui doit être traité tant par les acteurs de la recherche que par l'industrie automobile pour apporter des solutions technologiques innovantes. Dans les accidents impliquant des piétons, le premier contact est généralement localisé sur les membres inférieurs exhibant de fréquentes et nombreuses lésions pouvant être très sévères. Compte tenu des caractéristiques biomécaniques du membre inférieur, comment améliorer les critères de blessures existants pour contribuer au développement d'une voiture moins agressive pour les piétons ? La présente étude vise donc à promouvoir des améliorations significatives de critères de blessure des membres inférieurs pour la sécurité des piétons combinant des essais expérimentaux et des simulations numériques. Un modèle par éléments finis des membres inférieurs (modèle LLMS) a été utilisé et amélioré pour étudier les réponses mécaniques des membres inférieurs dans des conditions de chargement realists. Une attention particulière a été accordée sur la capacité du modèle à prédire séparément les blessures des os longs et celles de l'articulation du genou pour développer deux critères de blessures distincts. Pour le tibia, la nature de sa structure et les conditions de chargement qui lui sont appliquées nous ont conduit à proposer une courbe quadratique de moment en flexion qui tient compte de différents points d'impact. Pour le genou, le critère de blessure a été établi à partir d'une fonction combinant cisaillement latéral et flexion latérale. Ce critère permet de hiérarchiser la nature et la sévérité des lésions en fonction du mécanisme de blessure prépondérant. / Pedestrian safety is a worldwide concern, which needs to be investigated by both vehicle manufacturers and researchers to approach innovative solutions. In car-Pedestrian accidents, lower limbs have been demonstrated to be the most frequently injured body region of the pedestrian. Given the biomechanical features of lower limbs, how the existing injury criteria could be improved to aid the development of a pedestrian friendly car? The current study aims to promote significant improvements in the injury criteria of lower limbs for pedestrian safety combining experimental tests and numerical simulations. A finite element lower limb model (LLMS model) was used and improved to investigate the mechanical responses of lower limbs in the loading conditions reflecting the car-Pedestrian impact. A particular attention was paid on the model ability of predicting separately the injuries of long bones and knee joints to develop the corresponding injury criteria. With regard to the tibia structure and its loading condition in pedestrian accidents, we proposed a quadratic curve of bending moments to tibia locations as its injury tolerance. Given dominant injury mechanisms of the ligaments, the knee injury criterion was established as a function of combined joint kinematics including lateral bending and lateral shearing. Moreover, these criteria are relevant with the previous and current experimental test results. Finally, the efficiency of the proposed criteria was evaluated by a parametric study of the realistic car-Pedestrian impact conditions.

[pt] Análise modal consiste na caracterização de um sistema através dos seus parâmetros modais. Quando a principal excitação é causada pelo ambiente em que o sistema está inserido, essa caracterização é definida como análise modal operacional (OMA). Nestes casos, os forçamentos não são conhecidos (mensuráveis) e apenas as respostas são monitoradas. Por terem natureza aleatória, esses sinais precisam ser incorporados ao modelo numérico através de processos estocásticos. O principal objetivo desta dissertação consiste em descrever as técnicas de identificação em OMA. Para isso, duas vertentes foram criadas, uma teórica e outra experimental. Na parte teórica, as hipóteses necessárias para a identificação de um sistema por OMA são apresentadas. Uma análise dos erros causados por sinais ruidosos também é feita, permitindo que a sensibilidade dos métodos seja avaliada. Além de contemplar os principais métodos de identificação, dois novos métodos são propostos. Ambos foram desenvolvidos a partir da Decomposição Ortogonal Própria (POD) e combinam uma eficiência computacional com a possibilidade de quantificar as incertezas dos parâmetros. Na vertente experimental, o objetivo é ilustrar e validar a identificação de estruturas. Para isso, três diferentes bancadas foram criadas: um prédio de dois andares, uma pá eólica e uma ponte suspensa. Após a construção, essas estruturas foram devidamente instrumentadas por diferentes sensores. Um sistema de aquisição dados foi montado através de hardwares comerciais e analisados através de uma interfase gráfica desenvolvida especialmente para OMA pelo Laboratório de Vibrações. / [en] Modal analysis consists in the characterization of a system through its modal parameters. When the main excitation source is the system s environment, this characterization is defined as operational modal analysis (OMA). On those cases, the forces are unknown (not measured) and only the responses are monitored. Because of there random nature, those signals are incorporated into the numerical model as stochastic processes. The main goal of this dissertation is to describe the identification techniques in OMA. Therefore, two different approaches were created: a theoretical one and an experimental one. In the theoretical part, the required hypotheses for system s identification with OMA are presented. An analysis of the errors caused by noisy signals are also performed, allowing the method s sensibility to be evaluated. Besides the standard identification methods, two new ones are proposed. They both has been developed as extension of the Proper Orthogonal Decomposition (POD) and combine an efficient computational process with the possibility of quantify the parameters uncertainties. In the experimental approach, the goal is to illustrate and validate the identification of structures. Therefore, three different test bench were created: a two floor building, a wind turbine blade and a cable-stayed bridge. After their construction, those structures were proper instrumented with different sensors. A data acquisition system were built using commercial hardwares and analyzed through a graphic interface specially made for OMA and developed in the vibration laboratory.

L’objectif de ce travail de thèse est de développer une approche analytique permettant de définir la charge ultime d’une poutre cellulaire à ouvertures sinusoïdales. En effet, l’évolution des techniques de production a permis le développement d’une nouvelle forme de poutre cellulaire munie d’ouvertures sinusoïdales : la poutre AngelinaTM. Cette nouvelle forme d’ouverture implique de nouveaux modes de ruine. De ce fait, en vue de développer un modèle de calcul analytique adapté à cette nouvelle forme d’ouverture, une campagne d’essais expérimentaux a été menée sur des poutres cellulaires à ouvertures sinusoïdales à grande échelle (≈10m). Au travers de ces études expérimentales sur trois configurations de poutre, nous avons montré que le principal mode de ruine est lié à la flexion Vierendeel. En effet, la flexion locale des membrures de l’ouverture la plus sollicitée engendre soit la formation de 4 rotules plastiques aux 4 coins de l’ouverture, soit l’instabilité locale des parois d’âme comprimées. Un modèle aux éléments finis a été développé sur le logiciel SAFIR afin d’analyser les différents modes de ruines observés. Ce modèle a été validé sur la base des résultats expérimentaux et nous a permis d’identifier deux points particuliers : d’une part l’existence d’un maintien rotationnel entre le montant intermédiaire et la paroi d’ouverture et d’autre part, la ruine de l’ouverture ne se produit qu’au travers d’un mécanisme combinant les ruines des différents quarts d’ouverture. Une seconde campagne d’études expérimentales et numériques a ensuite été menée sur des parties isolées, extraites des poutres préalablement testées, afin d’étudier de manière locale le comportement à la flexion des quarts d’ouverture. Ces études ont servi à valider un second modèle aux éléments finis, développé sur le logiciel Cast3m. Celui-ci nous a permis, au travers d’une étude paramétrique, de quantifier le maintien rotationnel apporté par le montant intermédiaire sur la paroi d’âme d’ouverture adjacente. Cette étude a confirmé l’importance de la rigidité apportée par le montant intermédiaire aux parois d’âme adjacente. Ainsi, cet apport de rigidité doit être pris en compte dans l’approche analytique pour définir de manière réaliste la résistance au voilement local des différentes parties d’une ouverture sinusoïdale. Finalement, cette thèse a abouti au développement d’un nouveau modèle analytique de calcul de la résistance ultime des parois d’une ouverture sinusoïdale. Du fait des éventuelles instabilités locales, le modèle analytique s’est appuyé sur des éléments théoriques de stabilité des plaques. De plus, une étude numérique détaillée du mécanisme de ruine d’une ouverture isolée nous a permis de justifier une approche cinématique de ruine de l’ouverture sinusoïdale. Cette approche combine les résistances ultimes des différents quarts d’ouverture. Le modèle analytique proposé permet de considérer à la fois la résistance ultime de chaque partie de l’ouverture et leurs modes de ruine. Une étude comparative avec des résultats numériques a montré que ce modèle est fiable et représentatif de la réalité pour caractériser l’état limite ultime des poutres cellulaires à ouvertures sinusoïdales. / The aim of this thesis is to develop an analytical approach so as to define the ultimate failure load of cellular beams with sinusoidal openings. Indeed, the evolution of the conception techniques led to the development of a new opening shape for cellular beams: the sinusoidal openings (AngelinaTM beam). This new opening shape involves new failure modes at ultimate limit state and cannot be calculated with existing methods. Thus, experimental tests have been carried out on full scale cellular beams with sinusoidal openings (≈10m span). It has been shown, through those experimental studies led on three beam configurations, that the main failure mode is linked to the Vierendeel mechanism. At ultimate limit state, the local bending of the members of the most stressed opening leads to either the formation of four plastic hinges or the local buckling of the compressed opening web panels. A finite element model has been developed on the software SAFIR in order to better understand the different observed failure modes. This model has been validated on the basis of the experimental results and allowed identifying two main points: firstly, the existence of a rotational restraint between the intermediate web-post and the opening web panel and secondly, the failure of the sinusoidal opening corresponds to a mechanism combining the failure of each opening quarters. A second experimental and numerical test campaign has been conducted on isolated parts of the previous tested beams, in order to study locally the behavior of the opening quarters under local bending. Those studies allowed validating a finite element model developed on Cast3m software. This model has been used for a parametrical study which allowed quantifying the rotational restraint supplied by the intermediate web-post on the adjacent opening panel. This study confirmed the importance of the stiffness supplied by the intermediate web-post to the opening panels. Thus, it has to be taken into account to get a representative analytical failure load of each opening quarter. Finally, this thesis led to the development of a new analytical model for the calculation of the ultimate strength of the different opening parts. Due to the possible local buckling, the model is based on theoretical elements on the stability of plates. Furthermore, a detailed numerical study of the mechanism of failure of an isolated opening allowed justifying a cinematic approach for the failure of the opening. This approach combines the ultimate strength of each opening parts. The proposed analytical model permits to consider each opening quarter failure mode and strength. A comparative study with finite element results has showed that this model is reliable and representative of reality for defining the ultimate limit state of cellular beams with sinusoidal openings.

CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / CNPq - Conselho Nacional de Desenvolvimento Científico e Tecnológico / FAPEMIG - Fundação de Amparo a Pesquisa do Estado de Minas Gerais / INCT-EIE - Instituto Nacional de Ciência e Tecnologia De Estruturas Inteligentes em Engenharia / Os sistemas de suspensão automotivos são projetados para permitir que o condutor tenha controle total do veículo. Esses sistemas devem garantir com eficiência o isolamento de vibração para o interior do automóvel, a aderência entre os pneus e o solo e a estabilidade do veículo durante a execução de manobras que envolvam mudança de direção. Neste trabalho foi conduzida uma investigação experimental sobre o comportamento dinâmico de um veículo de passeio da categoria hatch compacto premium. Manobras específicas de handling e ride foram consideradas nos testes físicos, a fim de avaliar a resposta do sistema de direção e o conforto dos passageiros. Handling se refere ao modo como o veículo se comporta durante a execução de manobras de mudança de direção e ride se relaciona à forma como a suspensão do veículo responde as irregularidades de pista durante o ato de dirigir. O trabalho de pesquisa contempla a definição de uma metodologia aplicada ao desenvolvimento de um modelo completo de veículo, através do método de multicorpos. Na modelagem matemática, a maioria dos componentes de suspensão foram considerados como rígidos, visto que as deformações elásticas são suficientemente pequenas, podendo assim serem consideradas desprezíveis. No entanto, é considerada a presença de alguns elementos flexíveis, em particular a barra estabilizadora e o eixo de torção, que se revelam essenciais na tentativa de construção de um modelo capaz de reproduzir adequadamente os efeitos não lineares. Nesse sentido, a barra estabilizadora foi representada como um corpo flexível, com o objetivo de incluir a sua não linearidade geométrica no modelo. Já a modelagem do eixo de torção foi baseada em uma técnica de cossimulação que utiliza um solver de multicorpos e um solver externo de elementos finitos para análise não linear. Simulações do comportamento dinâmico foram realizadas a fim de verificar a abrangência do modelo e correlação com os dados experimentais. O estudo de ride é apresentado enfatizando a métrica necessária para quantificar o conforto do veículo, de acordo com a norma ISO 2631-1. Os dados coletados experimentalmente foram processados no domínio da frequência e do tempo utilizando o software LMS Test.Lab. O processo de construção e simulação do modelo virtual foi realizado utilizando o software LMS Virtual.Lab Motion para a simulação de multicorpos e o LMS Samcef MECANO para a simulação de elementos finitos. / Automotive suspension systems are designed to allow the driver full control of the vehicle. These systems must efficiently ensure the vibration insulation of the car cabin, the tire grip on the road and the vehicle’s stability during turning maneuvers. In this study, an experimental investigation of the dynamic behavior of a subcompact premium car was conducted. Typical ride and handling maneuvers were considered in the physical tests in order to evaluate the steering response and passengers comfort. Vehicle handling refers to the way that the vehicle performs during turning maneuvers, and ride to how the vehicle suspension responds to the track irregularities during the act of driving. This work describes the methodology used for the development of a full vehicle model through the multibody method. In mathematical modeling, the majority of vehicle suspension components were included in the model as rigid bodies, due to the fact the elastic deformations are sufficiently small and hence negligible. However, there is the presence of some flexible elements, in particular the stabilizer bar and the twist beam, which are essential in the attempt to build a model capable of properly reproducing the nonlinear effects. Accordingly, the stabilizer bar was represented as a flexible body, in order to include geometric non-linearity into the model. The modeling of the twist beam was based on a co-simulation technique that uses a multibody solver and an external nonlinear solver for finite element method analysis. Dynamic behavior simulations were performed to verify the scope of the model and correlated with the experimental data. The ride comfort study was carried out emphasizing the required metric to quantify the vehicle comfort according to ISO 2631-1. The data collected were processed and analyzed in frequency and time domain using the LMS Test.Lab software. The building and simulation of the virtual model was performed using the LMS Virtual.Lab Motion software for the multibody simulation and LMS Samcef MECANO software for the finite element simulation. / Dissertação (Mestrado)

As estruturas aeronáuticas estão sujeitas a diversas solicitações, devido principalmente às interações com o escoamento aerodinâmico, que podem causar distúrbios e vibrações, comprometendo seu desempenho. As medidas aerodinâmicas aplicadas em uma aeronave podem ser obtidas por simulações computacionais ou testes experimentais. No entanto, podem existir imperfeições na simulação computacional, como por exemplo, se conseguir reproduzir algumas condições de vôo real. Sendo assim, diversas pesquisas vêm sendo realizadas para solucionar estes problemas. Dentre elas estão os testes experimentais feitos em túnel de vento com modelos de escala real em diversas condições de vôo. Desta forma, a construção de um modelo físico de um aerofólio em escala reduzida e a implementação de sensores a este modelo torna-se uma ferramenta bastante importante para validar resultados teóricos e experimentais. Assim, nesse trabalho realizou-se a construção de um modelo de aerofólio NACA0012, o desenvolvimento de um mecanismo de fixação do modelo ao túnel de vento e a implementação de um controlador de oscilação forçada. O modelo físico realiza oscilações harmônicas, em regime não-estacionário. O objetivo do trabalho foi mapear as medidas de pressão atuantes sobre modelo ensaiado em regime estacionário e não-estacionário e fazer a comparação entre os dois casos. / Aeronautical structures are affected by many loads, most of them given by the aerodynamic flow interactions. These flow interactions may cause vibration leading to structural failure, such as cracks and fatigue. The aerodynamic flow interactions can be measured by experiment or predicted by computational simulation. Otherwise, computational simulations on its own are not reliable and can not reproduce a real flight condition, such as the mean atmospheric turbulence dynamic. Many researches has been done to solve these problems for computational simulations. One of them are the wind tunnel experiments with a full scale models in many flight conditions for posterior comparison. For a smaller wind tunnel, a small scale physical prototype well instrumented becomes an important solution to validate theoretical and experimental results. In the present work the construction of a NACA 0012 airfoil model, the development of a constraint mechanism and the implementation of a forced oscilation control system were done. The physical model oscilates with a given frequency. The aim of present work is to map the pressure measurements actuating on the model, testing it under a steady state condition and a transient condition for posterior comparison of both conditions.

Este trabalho aborda o estudo de modelos constitutivos a fim de analisar o comportamento mecânico de um biopolímero derivado de óleo de mamona (Ricinus communis). A importância deste trabalho se dá ao fato de: servir como roteiro de ensaio de materiais poliméricos; completar caracterização do material estudado além do regime viscoelástico, bem como aplicação da análise do comportamento do material além do regime viscoelástico linear. A aplicação dos modelos avaliados via Método dos Elementos Finitos (MEF) exigiu o levantamento das propriedades e do comportamento mecânico do biopolímero, bem como a preparação dos ensaios, com as devidas especificações sugeridas pela ASTM (American Society for Testing and Materials) para cada tipo de ensaio. Assim, foram obtidos os corposde- prova (CDP) para a realização dos ensaios mecânicos quase-estáticos de tração, compressão e flexão (monotônicos e cíclicos), bem como, ensaio para análise dinâmicomecânica (Dynamic Mechanical Analysis - DMA) para a obtenção de propriedades associada às parcelas viscosas do material. Com estes foram obtidos parâmetros inerentes a cada tipo de ensaio, permeados com uma cuidadosa revisão bibliográfica sobre as implicações para a realização de cada ensaio. Uma outra etapa foi a verificação de modelos de plastificação baseados na teoria de von Mises, Drucker-Prager e de viscoelasticidade implementados no programa comercial ABAQUS®. Sendo que o objetivo maior foi a comparação dos resultados experimentais obtidos com os modelos em MEF. Os resultados para tração monotônica obtiveram erro de 0,61%, os resultados de compressão monotônica apresentaram erro de 1,5% e as simulações para os carregamentos cíclicos de tração e compressão não foram tão bons quanto os anteriores. Por isso se justifica a criação do modelo fenomenológico utilizando os parâmetros do material que foram identificados. / This work develops the study involving constitutive models with the objective to analyze the mechanical behavior of a biopolymer obtained from the Castor Oil Polyurethane (Ricinus communis). The importance of this work is due to the fact that: serves as a test script for the use of polymer materials; complete the characterization of the material studied beyond the viscoelastic realm, as well as the application of the analysis of the behavior of the material beyond the linear viscoelastic domain. The application of the evaluated models by way of the Finite Element Method (FEM), required the gathering of the properties and mechanical behavior of the biopolymer, as well as the preparation of the tests, with the required specifications suggested by the ASTM (American Society for Testing and Materials) for each type of test. Therefore, there were obtained the body-tests in order to run the mechanical quasi-static traction tests, tensile, compression and flexion (monotonic and cyclical) dynamicmechanical analysis (DMA) in order to obtain the properties associated with the viscous parts of the material. With these the inherent parameters were obtained for each specimen, permeated with a careful biographical revision of the implications for the experimenting of each specimen. Another phase was the verification of laminated models based on the theory by Von Mises, Drucker-Prager and of the viscoelasticity implemented in the commercial program ABAQUS®. The main objective being the comparison of the experimental results obtained with the models in FEM. The results for the monotonic traction obtained a error of 0,61%, the results of monotonic comparison presented an error of 1,5% and the simulations for the cyclical charges of traction and compression were not as good as the former. Therefore it justifies the creation of the phenomenological model utilizing the parameters of the materials that were identified.

Le travail de thèse s’inscrit dans le cadre du projet TRAX. Il s’agit là du développement de moteurs électriques destinés à la traction des petits véhicules électriques urbains. Les caractéristiques clés d’une machine électrique pour une application de traction sont le couple, le rendement, la fiabilité, l’encombrement et la plage de vitesse à puissance maximale (dé-fluxage). Les machines électriques à aimants permanents répondent à ces exigences. C’est pourquoi ce travail de thèse s’est intéressé à l’étude des performances de machines à aimants permanents en proposant une étude comparative. Un état de l’art basé sur l’étude des brevets des machines électriques dans les applications automobiles est réalisé. Une description des dernières avancées des moteurs électriques principalement des structures à aimants permanents est fournit. Nous avons modélisé une première machine avec une méthode ana-lytique simplifiée basée sur la résolution des équations de Maxwell en 2D. Cette méthode est confrontée à une méthode numérique. Trois nouvelles machines sont définies à partir de la première en modifiant la configuration du rotor. La comparaison de quatre structures à aimants permanents est réalisée par des modèles numériques. Les performances à vide et en charge ainsi que le calcul des inductances dans l’axe direct et en quadrature sont évaluées. Les résultats théoriques sont comparés aux essais expérimentaux. / The thesis is part of the TRAX project. It deals with development of electric motors used for traction of small urban electric vehicles. The key characteristics of an electric machine for traction application are the torque, efficiency, reliability, size and flux-weakening. The permanents magnets electric machines meet these requirements. That’s why this thesis takes interest in the performances of permanents magnets machines by proposing a comparative study. A study of patents for electrical machines in automotive applications is realized. A description of the latest advances in electrical motors, mainly in permanent magnet structures, is provided. We started to model a first machine with a simplified analytical method based on the resolution of Maxwell's equations in 2D. This method is compared with a numerical method. Three new machines are defined from the first one by changing the configuration of the rotor. The comparison of four structures with permanent magnets is realized by numerical models. No load and load performances, as well as the calculation of inductances in the direct and quadrature axis, are evaluated. The theoretical results are compared with experimental tests.

När stadsbyggnadsprojekt planeras och städer omformas, var kommer medborgares kunskap om sin omgivning in? Hur behåller eller skapar medborgarna en anknytning till stadens platser, när deras användning och identitet förändras? Om staden ska vara en allmän rättighet krävs det att den växer fram kollektivt. Därför måste medborgares kunskap tas till vara på i stadens utveckling och i konkreta stadsbyggnadsprojekt. Det är svårt att se hur medborgare kommer få en koppling till dessa platser när de under en lång tid av stadsomvandlingen är avskärmade från den. Hur kan dessa platser, istället för att exkludera medborgare, bli en del av deras vardag redan under planerings- och förändringsprocesser? Hur kan medborgarnas delaktighet i planerings- och byggprocessen vara med om att bygga upp värden för platsers framtida användare?I Jubileumsparken i Göteborg används en metod planerarna kallar platsbyggnad. Arbetet bygger på att koppla samman medborgare med platsen under planeringen av den nya stadsdelen i Frihamnen genom att skapa urbana prototyper. Prototyperna öppnar upp för medborgarna att använda och utveckla platsen medan den planeras och tar fysisk form.Genom att prototyperna är i ett konstant flöde av användning och omvandling kan nya förståelser av hur planering kan gå till och vad platsen kan bli skapas. Prototyperna hjälper till att gå från något flytande (planer, idéer, visioner) till något fast.I studien ställer vi oss frågorna: var kommer idén om prototypprojekt ifrån? Hur har idén vuxit fram? Hur har prototyperna utvecklats och förändrats? Hur förstår och använder olika aktörer prototyperna och hur fungerar de i arbetet med Jubileumsparken?Prototyperna i sig själva hamnar i ett gränsland mellan aktörers relationer till prototyperna. Kontrasten av aktörernas relation till prototyperna gör det svårt att definiera vad prototyperna egentligen är, men genom att för en stund gör relationerna till något fast kan vi studera dem. När prototyperna är stabila och relationerna inte längre kommer omvandlas, och inga nya relationer kommer skapas, så har de kanske slutligen övergått till något fast. Men kommer de någonsin bli permanenta? Kanske är de bara i ett fast tillstånd för en stund? De är fasta objekt så länge inga relationer skapas eller omvandlas. / When urban construction projects are planned and cities are transformed, where will citizens’ knowledge of their surroundings come in? How do the citizens create or keep an attachment to the city’s places when their use and identity change? If the city is to be a universal right, it is required that it grows collectively. Therefore, citizens’ knowledge must be taken into account in the city’s development and in concrete urban construction projects. It’s hard to see how citizens will get a connection to these sites when they are shielded from the urban transformation for a long time. How can these places, instead of excluding citizens, become part of their everyday lives during the planning and construction process? How can citizens’ involvement in the planning and construction process help to build up the values ​for site’s future users?Jubileumsparken in Gothenburg uses a method the planners call space building. The work is based on linking citizens with the site during the planning of the new district in Frihamnen by creating urban prototypes. Prototypes open up for citizens to use and develop the site while it’s being planned and taking physical form. Because the prototypes are in a constant flow of use and conversion, new understandings of how planning can be and how the site can be created. Prototypes help move from something floating (plans, ideas, visions) to something solid.In the study we are asking the following questions: where does the idea of ​​prototype projects come from? How has the idea emerged? How have prototypes evolved and changed? How do different actors understand and use prototypes and how do they work in Jubileumsparken?The prototypes themselves end up in a borderland between actors’ relations with the prototypes. The contrast of the actors’ relation to the prototypes makes it difficult to define what the prototypes really are, but by making the relationships solid for some time we can study them. When the prototypes are stable and the relationships will no longer be transformed, and no new relationships will be created, they may eventually have shifted to something fixed. But will they ever become permanent? Maybe they are just in a solid state for a while? They are fixed objects as long as no relationships are created or converted.

This thesis deals with numerical analyses of electromagnetic fields on small aircraft with composite parts as an innovative way for assessment of their inherent protection against electromagnetic effects of outside environment in all development stages. It is concentrated for procedures of creation of geometrically and materially complex models for simulating calculations in the time as well as frequency domains, execution of the simulations itself and comparisons of results between the internal electromagnetic calculations and executed experimental tests. Achieved results were verified on a simplified reference model of aircraft's fuselage and two aircraft prototypes VUT100 and EV-55 of the company Evektor, spol. s r. o.

The article presents the results of experimental tests of the liquid exchange level in a new design of a hydraulic cylinder in comparison with the classic one. Comparative results are presented, as well as the influence of the stroke range on the degree of liquid exchange. The results allow the empirical determination of the degree of real improvement of the process of liquid exchange in the cylinder during operation, and thus allow the initial determination of the reliability level increase in hydraulic cylinders. It should be emphasized that the presented results are a part of a research and implementation project carried out in cooperation between a university and an industrial partner. In addition, the presented test method of hydraulic cylinders is, in the opinion of the authors, an interesting proposition, which can be used by manufacturers of this type of components in the world.