The main target of this thesis was to detect objective changes in the implementation of four postural locomotor tests DNS and during walking. The movements were recorded using the optical MoCap - the kinematic analysis Qualisys. The particular interest of the investigation was to determine the current stabilization of the spine system in individual subjects aged 25 to 55 years, which was documented by means of the angular deflection of each segment, the flat segment deviation or the shift of the marker in a coordinate system. The measurement results were compared between ten individuals with LBP and ten persons without any difficulty who were placed into the control group. The data were collected using the software QTM and Visual3D and subsequently were statistically processed. A statistically significant difference was observed during walking when comparing the angular deflection of the pelvis to the chest at the rotation and lateroflexion (ř). The significant difference of the pelvis shift toward the chest during flexion and rotation (ř) was showed in a deep squat test, but the difference was not confirmed in lateroflexion (ř). Furthermore, no statistical difference of the lateral deflection of the same segment (pelvis or chest) (cm) in patients with LBP compared to all subjects during the...

L'agriculture est un secteur d'activité qui est confronté aujourd'hui à des objectifs d'accroissement de productivité pour subvenir aux besoins alimentaires de la population mondiale en pleine explosion démographique. Cependant, cette activité sollicite fortement les biens environnementaux tels que l'eau et le sol, et des solutions sont aujourd'hui recherchées pour limiter l'incidence des pratiques agricoles sur l'environnement. Les systèmes de guidage des véhicules agricoles font partie de ces nouvelles technologies qui contribuent à cet objectif, en offrant la possibilité d'assurer la précision du suivi des trajectoires dans les parcelles, et de favoriser ainsi l'efficacité et la qualité du travail agronomique réalisé. Des fonctionnalités essentielles font néanmoins aujourd'hui défaut à ces systèmes. Citons la capacité à compenser la marche en crabe du véhicule sur les terrains glissants en pente, la capacité à contrôler les trajectoires des outils agricoles traînés, et la capacité à effectuer certaines manoeuvres en zone de fourrière. Ce travail de thèse aborde l'ensemble de ces problématiques au travers l'étude de la commande en milieu naturel de robot mobile poly-articulé à roues (RMPA), composé d'un véhicule " tracteur " à deux trains directeurs associé à n remorques passives à attache déportée. Une modélisation cinématique étendue est d'abord adoptée pour tenir compte des effets induits par les faibles conditions d'adhérence sur le comportement global du RMPA. Les variables de glissement introduites sur chacun des trains directeurs et roulants sont estimées à l'aide d'un observateur bâti à la manière d'une loi de commande. La trajectoire de référence à suivre gamma est quant à elle préalablement apprise ou construite à l'aide de primitives élémentaires et d'arcs de clothoïdes pour générer les manoeuvres de demi-tour. En premier lieu, les deux trains directeurs du RMPA sont exploités pour contrôler avec précision non seulement l'écart latéral mais également l'écart angulaire du véhicule " tracteur " par rapport à gamma : la commande du train directeur avant est basée sur la transformation du modèle en un système chaîné, conduisant à un découplage exact des performances latérales et longitudinales, puis sur des techniques de linéarisation exacte pour assurer la régulation latérale. La commande du train directeur arrière se base sur la dynamique de l'écart angulaire pour compenser les glissements et asservir cet écart sur le point de fonctionnement choisi. En second lieu, ces commandes sont étendues pour asservir latéralement la ieme remorque du RMPA le long de gamma : une approche en cascade est utilisée pour traduire une commande virtuelle de la ieme remorque en terme de commande du train directeur avant du véhicule " tracteur ". La commande longitudinale du RMPA est quant à elle basée sur une stratégie de commande prédictive à modèle interne, afin de suivre avec précision le profil de vitesse associé à gamma. De nombreuses expérimentations en conditions réelles, effectuées sur un RMPA composé d'un véhicule " tracteur " à deux trains directeurs et d'une remorque passive à attache déportée, viennent valider les différentes approches présentées dans ce mémoire et permettent d'apprécier les performances des lois de commande proposées. / Agriculture has today the challenge to increase its productivity in order to supply enough food for the growing needs of the world population. However, this activity strongly damages environmental ressources as water and soil, and new solutions are today required to reduce the impact of agricultural practices on environment. Automatic guidance systems for farm vehicles are some new technologies that contribute to this objective, allowing accurate path following in the fields and therefore improving efficiency and quality of the agricultural work carried out. Essential functionalities are however absent in these systems, as the capacities to compensate for the crabway motion of the vehicle on sliding sloping fields, to control the trajectories of the towed implement,and to perform U-turn maneuvers in headland. This thesis studies these problems through the control in presence of sliding of a poly-articulated wheeled mobile robot called RMPA, composed of a four-wheel-steering vehicle and n passive trailers hooked up at some distance from the rear axle of the previous one. An extended kinematic model of the RMPA is first used in order to take into account for the sliding effects on the overall behaviour of the robot. The sliding parameters, introduced on each rolling and steering axle of the RMPA, are estimated using a state observer built as a control law. The reference path [gamma] to be followed is either previously learned or specially planned using elementary primitives connected together with pieces of clothoid to produce the U-turn maneuvers. In a first step, both front and rear steering actuations of the robot are used to accurately control both lateral and angular deviations of the RMPA's four-wheel-steering vehicle with respect to [gamma] : the control of the front steering wheels is based on the transformation of the extended kinematic model into a chained system, allowing to dissociate the lateral and longitudinal commands, and on exact linearization techniques in order to servo lateral deviation. The control of the rear steering wheels is built from the angular deviation dynamic and ensures the convergence of the vehicle deviation to the desired set point. In a second step, these control laws are extended to control the lateral deviation of the ith trailer of the RMPA with respect to [gamma] : a backstepping approach is proposed to calculate the control law for the RMPA's front steering wheels from the study of a virtual control law for the ith trailer. Finally, the longitudinal control law of the RMPA is based on model predictive control, in order to accurately follow the velocity references linked to [gamma]. Numerous experiments relying on an actual RMPA, composed of a passive trailer hooked up at some distance from the rear axle of a four-wheel-steering vehicle, permit to validate the various approaches presented in this thesis and to appreciate the capabilities of the proposed control laws.

[pt] Simuladores de movimentos são sistemas mecatrônicos que reproduzem as principais atitudes e movimentos de um veículo. Neste estudo serão analisados simuladores baseados em mecanismos com 3 e 6 graus de liberdade. No segundo caso, o mecanismo é capaz de reproduzir todos os ângulos de atitude (rolagem, arfagem e guinada) e todos os deslocamentos lineares (lateral, vertical e longitudinal) com limitações, porém com amplitude suficiente de modo a possibilitar os principais movimentos associados ao veículo. O uso de transdutores de deslocamento linear nestes mecanismos articulados introduzem elevados efeitos de inércia, além de aumentar a massa dos mesmos, diminuindo sua relação carga/peso e sua eficiência. Atualmente, o grande desenvolvimento de sensores do tipo unidade de medição inercial (IMU) aumentou a disponibilidade destes no mercado e reduziu muito seu custo. Como se trata de acelerômetros triaxiais em conjunto com girômetros também triaxiais, sensores como este podem ser usados para determinar a posição e a orientação no espaço de mecanismos com seis graus de liberdade, como a Plataforma Stewart. Neste trabalho será desenvolvida uma metodologia para modelagem da cinemática de mecanismos paralelos baseada nos derivativos de suas matrizes jacobianas. Esta metodologia é avaliada em um mecanismo paralelo plano de três graus de liberdade e em uma Plataforma Stewart. Com a metodologia de modelagem validada, é implementada uma estratégia de controle baseada no uso de um sensor tipo central inercial para o controle de posição, velocidade e aceleração destes mecanismos. Os resultados das simulações indicam a possibilidade do uso destes sensores nestes tipos de equipamentos e apontam para a necessidade de avaliar esta metodologia em testes experimentais. / [en] Movement simulators are mechatronic systems that reproduce the main attitudes and movements of a vehicle. In this study are examined simulators based on 3 and 6 degrees of freedom mechanisms. In the second case, the mechanism is able to reproduce all the attitude angles (roll, pitch and yaw) and all the linear displacements (sway, heave and surge) with limitations, but with sufficient amplitude to enable the main movements associated with the vehicle. The use of linear displacement transducers in these articulated mechanisms introduce high inertia effects and increase the mass, decreasing the load/weight ratio and efficiency. Currently, the great development of the inertial central type sensors (IMU – Inertial measurement unit) increased the availability of these transducers on market and greatly reduced cost. Since this is a conjunct of triaxial accelerometers with triaxial gyrometers, sensors such as these ones can be used to determine the position and orientation in space of mechanisms with six degrees of freedom, such as the Stewart Platform. In this work it will be developed a methodology for modeling the kinematics of parallel mechanisms based on derivatives of their jacobian matrices. This methodology is evaluated in a planar parallel mechanism of three degrees of freedom and on a Stewart Platform. With the modeling methodology validated, a control strategy based on the use of an inertial unit type sensor for controlling the position, velocity and acceleration of these mechanisms is implemented. The simulations results indicate the possibility of using these sensors in these types of equipment and point to the need to evaluate this methodology in experimental tests.

In dieser Arbeit wird das lokal aufgelöste Deformationsfeld einzelner (In,Ga)N/GaN Drähte mit Hilfe nanofokussierter Röntgenbeugung und der Methode der Finiten Elemente untersucht. Hiermit soll ein Beitrag zum grundlegenden Verständis der optischen Eigenschaften geleistet werden, die durch das Deformationsfeld maßgeblich beeinflusst werden. Zunächst wird die Abhängigkeit der vertikalen Normalkomponente, epsilon_zz, des elastischen Dehnungstensors von der Geometrie eines axialen (In,Ga)N/GaN Nanodrahtes diskutiert. Dabei wird ein signifikant negativer epsilon_zz-Wert beobachtet, sobald das Verhältnis von Nanodrahtradius und (In,Ga)N-Segmentlänge gegen eins strebt. Auffallend große Scherkomponenten und eine konvexe Verformung der äußeren Oberfläche begleiten das Auftreten des negativen epsilon_zz- Wertes und sind die Ursache dieses Effekts. Durch eine Ummantelung von GaN-Nanodrähten mit einer (In,Ga)N-Schale lässt sich die aktive Fläche und somit die potentielle Lichtausbeute pro Fläche im Vergleich zu planaren Strukturen deutlich erhöhen. Es wurde jedoch festgestellt, dass das entlang der Drahthöhe emittierte Licht rotverschoben ist. Um den Ursprung dieses Phänomens zu beleuchten, wird das lokale Deformationsfeld mit Hilfe nanofokussierter Röntgenbeugung vermessen. Durch die gute räumliche Auflösung ist es möglich, das Deformationsfeld innerhalb einzelner Seitenfacetten zu untersuchen, wobei ein deutlicher Gradient festgestellt wird. Basierend auf dem mit der Methode der Finiten Elemente simulierten Deformationsfeld und kinematischen Streusimulationen, ist es möglich, den Deformationszustand in einen In-Gehalt zu übersetzen. Wenn neben dem Deformationsfeld auch der strukturelle Aufbau in der Simulation berücksichtigt wird, kann der In-Gehalt mit noch größerer Genauigkeit bestimmt werden. / In this thesis, nanofocus x-ray diffraction and the finite element method are applied to analyze the local strain field in (In,Ga)N/GaN nanowires and micro-rods which are discussed as candidates for a plethora of future optoelectronic applications. However, to improve and tailor their properties, a fundamental understanding on the level of individual objects is essential. In this spirit, the dependence of the vertical normal component, epsilon_zz, of the elastic strain tensor on the geometry of an axial (In,Ga)N/GaN nanowire is systematically analyzed using the finite element method. Hereby, it is found that if the ratio of nanowire radius and (In,Ga)N segment length approaches unity, a significantly negative epsilon_zz value is observed. This stands in stark contrast to naive expectations and shows that the common knowledge about planar systems where epsilon_zz would always be greater or equal zero cannot easily be translated to nanowires with an equivalent material sequence. As the origin of this effect significant shear strains are discussed which go along with a convex deformation of the outer surface resulting in a highly complex strain distribution. The increased active area of core-shell (In,Ga)N/GaN micro-rods makes them promising candidates for next-generation light emitting diodes. However, it is found that the emission wavelength is significantly red-shifted along the rod height. To shed light on the origin of this phenomenon, nanofocus x-ray diffraction is applied to analyze the local strain field. Due to the high spatial resolution it is possible to investigate the strain field within individual side-facets and to detect a significant gradient along the rod height. Based on the deformation field simulated using the finite element method and subsequent kinematic scattering simulations it is possible to translate the strain state into an In content.

Made available in DSpace on 2017-07-21T14:19:34Z (GMT). No. of bitstreams: 1 Idomar Cerutti.pdf: 3056980 bytes, checksum: 1f558a41e8107db9e91550dc01470a55 (MD5) Previous issue date: 2012-07-23 / The use of geo-referenced information in precision farming has increased greatly in the last decade. Furthermore, the decrease in the cost of GPS reception equipment has made possible their use by people who did not previously have access to this technology. This research aims to evaluate the precision and accuracy of the GPS receptor model Gstar GS-87, to understand its applicability for information systems embedded in agricultural systems. This research is part of the Agrobot project, which is being developed at the Laboratory of Automation and Control, State University of Ponta Grossa. An embedded computer Friendly ARM, model Mini6410 was used, with operating system Linux version 2.6.38. Static absolute surveys were conducted at three geodesic marks: Castro (96005), UEPG Campus (91643) and Pilar UFPR 1000.Several kinematic surveys were also carried out to compare the GPS coordinates collected by GPS receptor Gstar GS-87, with data collected by Geodetic GPS receptor Leica GX-1230. The static surveys from this research show that the GS-87 demonstrated a dimensional accuracy of +/- 8.19 m, with standard deviation of 11.43 m, and bi-dimensional accuracy +/- 13.78 m with a standard deviation of 14.26 m. In relation to kinematic surveying the receiver had an accuracy of +/- 3.70 m with a standard deviation of 1.88 m. A time difference of 15 sec between the data collected for both receptors was observed. Also was observed that the GPS receptor Gstar GS-87 recorded changes of coordinates properly when it was on the move with a speed equal to or greater than 9 km/h. It can be argued that the GPS receiver Gstar GS-87 can be used in an embedded information system, where the need for precision and accuracy are consistent with the data presented in this study. / O uso de informações georreferenciadas na agricultura de precisão tem crescido muito na última década. Além disso, o decréscimo do custo dos equipamentos de recepção GPS tem tornado possível o seu uso por produtores agrícolas que estavam distantes de tal tecnologia. Esta pesquisa objetiva avaliar a precisão e acurácia de receptor GPS modelo Gstar GS-87, para compreender sua aplicabilidade em sistemas de informação embarcado com sistema agrícolas. A pesquisa é parte do projeto Agrobot, que está sendo desenvolvido no Laboratório de Automação e Controle da Universidade Estadual de Ponta Grossa. Foi utilizado computador embarcado Friendly ARM modelo Mini6410, com sistema operacional Linux versão 2.6.38. Foram realizados três levantamentos absolutos estáticos nos marcos geodésicos Castro (96005), UEPG Campus (91643) e UFPR Pilar 1000, bem como diversos levantamentos absolutos cinemáticos para comparar as coordenadas coletadas pelo receptor GPS Gstar GS-87, com os dados coletados pelo receptor GPS geodésico Leica GX-1230. Como resultado da pesquisa, em levantamentos absolutos estáticos, pode-se afirmar que o receptor apresenta acurácia idimensional de +/-8,19 m, com desvio padrão de 11,43 m e precisão bidimensional +/- 13,78 m com desvio padrão de 14,26 m. Em levantamentos absolutos cinemáticos o receptor tem uma precisão de +/- 3,70 m, com desvio padrão de 1,88 m. Também se observou uma diferença de tempo de 15 seg entre os dados coletados por ambos os receptores. Ainda foi observado que o receptor GPS Gstar GS-87 registrava adequadamente alterações de coordenadas quando estava em deslocamento com velocidade igual ou superior a 9 km/h. É possível afirmar que o receptor GPS Gstar GS-87 pode ser utilizado em sistemas de informação embarcado, onde a necessidade de precisão e acurácia sejam compatíveis com os dados apresentados nesta pesquisa.

La Méditerranée se situe dans une zone de convergence lente entre les plaques Eurasienne et Africaine (~5 mm/an), où des restes d'anciens bassins Téthysiens sont progressivement consommés par le retrait rapide de zones de subductions (~20-30 mm/an sur la zone de subduction Hellénique). En Méditerranée Orientale, une transition collision-subduction se produit dans l'Ouest de la Grèce (collision de la Plateforme Apulienne au nord et subduction Hellénique au sud), pratiquement à l’extrémité du Golfe de Corinthe et dans une région de propagation potentielle de la faille Nord Anatolienne. Afin d'étudier la cinématique actuelle de l'Ouest de la Grèce, nous adoptons une approche multi-échelle de la déformation:(1) Une modélisation grande échelle du champ de vitesses crustale horizontales mesuré par géodésie est effectuée afin de contraindre la cinématique au voisinage de l'Ouest de la Grèce, à la fois à terre et en mer. Un résultat majeur est qu'une zone d'extension distribuée N-S s'étendant de la Bulgarie à l'Est du Golfe de Corinthe a pour conséquence de désactiver la terminaison Ouest de la faille Nord Anatolienne dans le nord de la Mer Egée. Cette extension d’échelle régionale pourrait être causée par le retrait du slab Hellénique. (2) Une étude tectonique active permet d'établir une cartographie précise des failles actives de la région, leur chronologie relative et une estimation de leur vitesse de déplacement. Le demi-graben actif du Golfe Amvrakikos et la faille active N155° de Katouna-Stamna, qui constituent les frontières Nord et Est d'un bloc Iles Ioniennes-Akarnanie (IAB), sont caractérisés par des vitesses géologiques d'au moins ~ 4 mm/an et des vitesses mesurées par GPS de l'ordre de ~10 mm/an. Ce bloc IAB est limité à l'Ouest par la faille transformante de Céphalonie et semble se comporter de manière rigide.(3) Une fois les frontières du bloc IAB connues, nous montrons que le champ de vitesse GPS mesuré dans la région peut être entièrement expliqué par des effets transitoires de blocage élastique associés aux failles bordières de ce bloc. Le couplage sur l'interface de subduction n'a pas d'expression en surface, ce qui suggère qu'il doit être faible. Enfin, nous justifions l'existence d'un point triple de type Rift-Faille-Faille à la terminaison Ouest du Golfe du Corinthe. / The Mediterranean is a diffuse plate boundary zone between the slowly converging Eurasian and African plates (~ 5mm/yr), where remnants of old Tethyan basins are progressively consumed by fast trench retreat (~20-30 mm/yr at the Hellenic subduction zone). In Eastern Mediterranean, a collision-subduction transition occurs in Western Greece (collision of the Apulian Platform to the north and Hellenic subduction zone to the south), close to the westward Corinth Rift termination and in a region that may be potentially affected by the westward propagation of the North Anatolian Fault. We used a multi-scale deformation approach to investigate Western Greece active kinematics:(1) We run a large scale model of horizontal crustal velocities measured by GPS to constrain the kinematic boundary conditions of Western Greece, both onshore and offshore. A major result is the occurrence of distributed N-S extension spreading from Bulgaria to the Eastern Corinth rift, resulting in de-activation of the western termination of the North Anatolian Fault in North Aegean Sea. This large scale extension could be associated to the retreat of the Hellenic slab.(2) An active tectonics study has been performed to provide an accurate mapping of active faults in the region, to constrain their relative chronology and to estimate their geological slip-rate. The Amvrakikos Gulf active half-graben and the N155° active Katouna-Stamna Fault, which form the northern and eastern boundaries of a Ionian Island-Akarnania block (IAB), have geological slip rates of at least ~ 4mm/yr and GPS slip-rates of ~ 10 mm/yr. The IAB is bounded to the west by the Kefalonia transform fault and appears to behave rigidly.(3) Once the IAB boundaries are defined, we show that the velocity field measured by GPS in the region can be totally accounted by transient elastic loading along the IAB bordering faults. Subduction interface coupling has no surface expression, suggesting low coupling. Finally, we justify the occurrence of a Rift-Fault-Fault triple junction at the western termination of the Corinth Rift.

The main objective of this research is the development of a framework for the automatic generation of systems of kinematic and dynamic equations that are suitable for real-time applications. In particular, the efficient simulation of constrained multibody systems is addressed. When modelled with ideal joints, many mechanical systems of practical interest contain closed kinematic chains, or kinematic loops, and are most conveniently modelled using a set of generalized coordinates of cardinality exceeding the degrees-of-freedom of the system. Dependent generalized coordinates add nonlinear algebraic constraint equations to the ordinary differential equations of motion, thereby producing a set of differential-algebraic equations that may be difficult to solve in an efficient yet precise manner. Several methods have been proposed for simulating such systems in real time, including index reduction, model simplification, and constraint stabilization techniques. In this work, the equations of motion are formulated symbolically using linear graph theory. The embedding technique is applied to eliminate the Lagrange multipliers from the dynamic equations and obtain one ordinary differential equation for each independent acceleration. The theory of Gröbner bases is then used to triangularize the kinematic constraint equations, thereby producing recursively solvable systems for calculating the dependent generalized coordinates given values of the independent coordinates. For systems that can be fully triangularized, the kinematic constraints are always satisfied exactly and in a fixed amount of time. Where full triangularization is not possible, a block-triangular form can be obtained that still results in more efficient simulations than existing iterative and constraint stabilization techniques. The proposed approach is applied to the kinematic and dynamic simulation of several mechanical systems, including six-bar mechanisms, parallel robots, and two vehicle suspensions: a five-link and a double-wishbone. The efficient kinematic solution generated for the latter is used in the real-time simulation of a vehicle with double-wishbone suspensions on both axles, which is implemented in a hardware- and operator-in-the-loop driving simulator. The Gröbner basis approach is particularly suitable for situations requiring very efficient simulations of multibody systems whose parameters are constant, such as the plant models in model-predictive control strategies and the vehicle models in driving simulators.

Atomistic simulations are employed in this thesis to investigate defect nucleation and free volume of grain boundaries and nanocrystalline materials. Nanocrystalline materials are of particular interest due to their improved mechanical properties and alternative strain accommodation processes at the nanoscale. These processes, or deformation mechanisms, within nanocrystalline materials are strongly dictated by the larger volume fraction of grain boundaries and interfaces due to smaller average grain sizes. The behavior of grain boundaries within nanocrystalline materials is still largely unknown. One reason is that experimental investigation at this scale is often difficult, time consuming, expensive, or impossible with current resources. Atomistic simulations have shown the potential to probe fundamental behavior at these length scales and provide vital insight into material mechanisms. Therefore, work conducted in this thesis will utilize atomistic simulations to explore structure-property relationships of face-centered-cubic grain boundaries, and investigate the deformation of nanocrystalline copper as a function of average grain size. Volume-averaged kinematic metrics are formulated from continuum mechanics theory to estimate nonlocal deformation fields and probe the nanoscale features unique to strain accommodation mechanisms in nanocrystalline metals. The kinematic metrics are also leveraged to explore the tensile deformation of nanocrystalline copper at 10K. The distribution of different deformation mechanisms is calculated and we are able to partition the role of competing mechanisms in the overall strain of the nanocrystalline structure as a function of grain size. Grain boundaries are observed to be influential in smaller grained structures, while dislocation glide is more influential as grain size increases. Under compression, however, the resolved compressive normal stress on interfaces hinders grain boundary plasticity, leading to a tension-compression asymmetry in the strength of nanocrystalline copper. The mechanisms responsible for the asymmetry are probed with atomistic simulations and the volume-averaged metrics. Finally, the utility of the metrics in capturing nonlocal nanoscale deformation behavior and their potential to inform higher-scaled models is discussed.

In den letzten Jahrzehnten hat sich auf dem Gebiet der phänomenologischen Metallplastizität eine schleichende Revolution vollzogen. Dank der gestiegenen Rechenleistung, in Kombination mit ausgereiften numerischen Algorithmen, sind viele technisch relevante Problemstellungen einer zuverlässigen numerischen Analyse zugänglich gemacht worden. Beispielsweise ermöglicht die Metallumformsimulation, als häufigste Anwendung der Plastizitätstheorie, eine Analyse des Eigenspannungszustandes und der Rückfederung in plastisch umgeformten Halbzeugen und Bauteilen. Solche Simulationen sind für die Planung energie- und ressourceneffizienter Herstellungsprozesse sowie für die Ausnutzung der plastischen Tragfähigkeitsreserven von großer Bedeutung. Die Crashtest-Simulation ist die zweithäufigste Anwendung, die in der Automobilindustrie und auch zunehmend im Flugzeugbau eingesetzt wird. Aus der Notwendigkeit, das Verhalten metallischer Werkstoffe auf Bauteilebene hinreichend genau zu beschreiben, resultiert die Motivation für eine breit angelegte Studie zur Materialmodellierung. Dabei führt die beträchtliche Anzahl unterschiedlicher Phänomene und Effekte, die berücksichtigt werden müssen, zu einer großen Vielfalt von Materialmodellen. Da die Lösung komplizierter praktischer Probleme mit einem sehr großen numerischen Aufwand verbunden ist, wird der vorteilhafte phänomenologische Zugang bevorzugt. Bei der Konzeption von neuen phänomenologischen Materialmodellen müssen folgende Aspekte beachtet werden: die Genauigkeit bei der Beschreibung des Materialverhaltens; die Stabilität und Robustheit von zugehörigen numerischen Algorithmen; die numerische Effizienz; die zuverlässige Parameteridentifikation für einen möglichst großen Anwendbarkeitsbereich; die Anschaulichkeit und Einfachheit des Materialmodells. Im Allgemeinen stehen diese Anforderungen an ein "gutes Materialmodell" zwar in einem gewissen Widerspruch zueinander, bilden andererseits aber das Grundgerüst für eine systematische Studie. Obwohl sich die vorliegende Arbeit vordergründig an erfahrene Spezialisten im Bereich der Kontinuumsmechanik wendet, sind die darin präsentierten Modelle und Algorithmen auch für praktisch tätige Berechnungsingenieure von Interesse. / In the last decades, a creeping revolution was taking place in the area of the phenomenological metal plasticity. Due to the increased computational power, combined with refined numerical algorithms, many of technically relevant problems are now available for the numerical analysis. In particular, the metal forming simulation is a typical application of the metal plasticity. It enables the analysis of the residual stresses and spring back phenomena in plastically deformed workpieces and components. Such analysis is advantageous for planning of energy and resource-efficient manufacturing and for exploitation of plastic reserves of bearing capacity. The crash test simulation is the second most common application of metal plasticity, highly celebrated in the automotive industry and gaining increasing popularity in the aircraft industry. The need for sufficiently accurate description of metal behaviour on the macroscale motivates wide-ranging studies on material modelling. The large number of different effects and phenomena contributes to the large manifold of material models. The current work deals with the phenomenological approach, due to its great suitability for the solution of practical problems. The following aspects should be taken into account upon the construction of new phenomenological models: the accurate description of the material behaviour, the stability and robustness of the corresponding numerical algorithms, the numerical efficiency, the reliable parameter identification for a sufficiently large application area, the clearness and simplicity of the material models. In general, these requirements imposed on a "good material model" contradict each other. In this work, however, they are complimentary to each other and build a framework for a systematic study. Although this work is written primarily for experts on the continuum mechanics, the presented models and algorithms can be of interest for practically working engineers.

Rheumatoid Arthritis (RA) is a disease in which the body has "turned on itself", with its immune system attacking mobility. In RA, an immune mechanism attacks and destroys the joints and limits mobility, in some circumstances to the point of needing replacement of joints. The aim of this research is the development of a less costly, widely accessible, passive sensing technology that provides a quantitative assessment of RA and that monitors the therapeutic effectiveness on joint-debilitating diseases. The proposed solution relies on a quantitative evaluation of human gestures. Such a quantitative assessment supports the comparison between the motion capabilities of a patient and that of a healthy person, using a kinematic model of the human skeleton. Criteria for the classification of severity were established, and tables were generated to classify the levels of severity as a function of the measurements extracted from processed videos of a subject performing predefined movements. This research project, while contributing a new tool to the process of classification of RA level of severity, opens the way for using widely accessible digital imaging for diagnosing and monitoring the evolution of the illness. Replacing MRI or HRUS with a cheaper and more accessible technology would have a major impact on health care services. From the clinical point of view, the proposed techniques based on digital images processing combined with a monitoring approach based on infrared images that was previously developed may provide a utility of care for patients with RA, as well as an alternative and automated approach for early detection of RA and active inflammation at a critical time.