Dans le cadre du projet collaboratif FUI "HyPlate", cette étude apporte une contribution originale dans la compréhension des mécanismes impliqués lors de l'assemblage d'une pile à combustible de type PEMFC, à l'aide de la mesure ou de la prédiction des déformations et des contraintes mécaniques dans le cœur de pile ou MEA. Basée sur une analyse multi-échelle, une approche duale expérimentale et prédictive a été menée, comprenant le développement non seulement de nouvelles méthodes de mesures expérimentales mais également un modèle numérique 3D, basé sur la méthode des éléments finis. Le couplage des différents résultats expérimentaux et simulés a permis de déterminer, dans un premier temps, le niveau de contraintes (ou de déformations) dans les différents composants du stack en fonction des conditions d'assemblage, et d'analyser, dans un second temps, l'influence de différents paramètres, tels que les propriétés des matériaux des plaques bipolaires, le nombre de cellules et leur position. Il a notamment été montré que la distribution des déformations dans le cœur de pile diminuait avec le nombre de cellules et au centre du stack. Des modifications sur le système de serrage de la pile ont alors été proposées afin d'améliorer l'homogénéité de l'état mécanique global. Des mesures de force in-situ ont alors permis de valider certaines propositions et d'analyser l'influence de deux modes de serrage, en contrainte ou déformation imposée, sur la performance électrochimique de la pile. / Within the context of the FUI project "HyPlate", this thesis bring an original contribution in the understanding of the mechanisms implied during the assembly of a Proton Exchange Membrane Fuel Cell (PEMFC), through the measurements and the predictions of the mechanical stresses and strains in the fuel cell core, also known as the MEA. Based on a multi-scale analysis, a double approach experimental and predictive was followed, including not only the development of new experimental measurement methods but also a 3D numerical model, based on the finite element method. The results gathered from these two studies allowed us to determine, in a first step, the stress (or strain) level within the different stack components according to the assembly conditions, and to analyze, in a second step, the influence of different parameters such as the bipolar plate mechanical properties, the number of cells and their position. It was notably shown that the MEA strain distribution decreased with the number of cells and at the center of the stack. Some modifications of the clamping system were proposed in order to enhance the global mechanical state homogeneity. In situ measurements of the clamping force allowed us to validate some propositions made and to analyze the influence of two clamping modes, implying a constant stress or strain, on the electrochemical performance of the fuel cell.

Ce travail de thèse vise à identifier les mécanismes par lesquels la fraction volumique de charges, la distribution de tailles des charges, le comportement mécanique du liant et les propriétés d’adhésion liant/charge des propergols composites influent sur le comportement mécanique jusqu’à rupture de ces matériaux. Des calculs de microstructures 2D par éléments finis sont mis en œuvre pour caractériser qualitativement l’évolution de la microstructure du composite au cours d’une sollicitation de traction uniaxiale à faible vitesse de déformation. Ils prennent notamment en compte un modèle de zone cohésive pour représenter la décohésion à l’interface liant/charge et un critère original de ruine de la microstructure. Les résultats numériques sont favorablement comparés aux tendances obtenues expérimentalement sur propergols composites industriels et modèles. Par ailleurs, une validation de l’approche qualitative précédente est conduite en effectuant une confrontation quantitative du comportement mécanique et de la variation volumique d’un composite modèle, obtenus par simulation de microstructures 3D et par caractérisations expérimentales. Enfin, la tenue du propergol dans un assemblage propergol/lieur soumis à un test de pelage est étudiée expérimentalement. / This work aims at understanding the relationship between solid propellants particles volume fraction, particles size distribution, binder mechanical properties and binder/particles bonding with the mechanical behavior up to failure of these materials. Finite elements analyses on 2D microstructures are performed in order to qualitatively characterize the microstructure evolution throughout uniaxial tensile loading at small strain rate. These simulations account for the binder/particles debonding with a cohesive zone model and implement an original failure criterion. Simulation and experimental results are consistent. Besides, a quantitative comparison between simulations on 3D microstructures and experimental data is drawn in order to validate the above qualitative results. It is performed on a model composite and compares both the mechanical behavior and the volume variations. At last, the propellant failure during a peeling test of the liner/propellant structure is studied experimentally.

The diploma thesis deals with the loss of stability of thin-walled flue pipe at coal power plant. The problem of thin-walled structures is their propensity to the loss of stability due to abnormal conditions, for example a vacuum, effect of wind, snow and earthquake. The purpose is to find the optimal deployment of reinforcements so that the model meets the requirements of EN 1993-1-6. This required an evaluation of unreinforced version of the model to identify weaknesses and subsequently other configurations for the application of reinforcement. For determining the resistance the flue pipe to the loss of stability used primarily to access linear bifurcation analysis based on linear analysis, possibly materially nonlinear analysis. The result of work is a design of reinforcement of pipeline which under the requirements of the standard meets the latest model with a reserve of approximately 20 %.

Nowadays, the use of robots in industrial tasks is growing constantly. However, manual assembly is one area that is hard to make fully automated since manual assembly operations work with different shapes and products that require human finesse to do some operations. Humans, on the other hand, have a lot of limitations since this kind of task can be unergonomic and repetitive for operators, which can cause them stress, fatigue, repetitive stress injuries(RSI), and repetitive motion injuries. This project involved designing an insert for the gripper 2F-85 (version 3) that would allow the collaborative robot (UR5) to carry out more assembly tasks in order to relieve human workers of repetitive tasks. The insert has to handle cylindrical shapes in addition to bigger parts that the actual insert cannot handle due to its parallel stroke. For that, a detailed market analysis and insert research were conducted in the initial study. The new insert was then developed using a double-diamond design process. The needs were ranked using the Moscow prioritization method, and ideas were then generated using the brainstorming technique. The final concept was chosen using the weighted decision matrix method. After the final concept selection, computer-aided design (CAD) technology was employed to create the new insert's 3D model and its technical specifications. The mechanical behaviour of the new insert was analysed to reflect its range of workability, expressing the maximum force that it can withstand on each of its grip work surfaces without presenting plastic deformation. For this study, finite element analyses were conducted following the general method for linear structural analysis using Abaqus. Achieving an insert that can reach, transport, and assemble different shapes will help integrate collaborative robots into manual assembly processes, avoiding the cost of a new gripper.

[pt] Esta dissertação tem como objetivo principal estudar o comportamento dos taludes da mineração Pampa de Pongo, situada no Peru, em termos de deslocamentos e fatores de segurança contra ruptura por cisalhamento. As escavações atingem atualmente profundidades superiores a 900m com o corpo mineral seccionado por várias falhas geológicas que podem aumentar o potencial de risco de colapso dos taludes. As análises tensão x deformação foram executadas pelo método dos elementos finitos, em modelos bi e tridimensionais, considerando a existência e a ausência do sistema de falhas para melhor estimar e compreender a influência destas nos deslocamentos do maciço com o avanço das escavações. Este estudo também investigou as diferenças observadas nos resultados obtidos com dois programas comerciais de elementos finitos para solução de problemas geotécnicos (Phase2 e Plaxis 2D) tendo em vista as diferentes metodologias por eles empregadas na simulação de fraturas em meios contínuos. Nas análises de estabilidade os valores dos fatores de segurança determinados pelo método dos elementos finitos, em simulações 2D e 3D, foram também comparados com aqueles calculados por método de equilíbrio limite (método das fatias). De modo geral, observou-se que os efeitos das descontinuidades são maiores nos campos de deslocamentos horizontais e que também tendem a diminuir os valores de fator de segurança, inclusive para limites mínimos abaixo dos recomendados por normas brasileiras. / [en] This thesis aims to study the behavior of the Pampa de Pongo open pit mine, situated in Peru, in terms of displacements and safety factors against shear failure. Excavations currently reach depths greater than 900m and the orebody is sectioned by several geological faults that may increase the potential risk of collapse of embankments. The stress x strain analyses were carried out by the finite element method, with two and three dimensional models, considering the existence and the absence of the fault system, to better estimate and understand the influence of these discontinuities in the displacements of the rock mass with the advancement of excavations. This study also investigated the differences in results obtained with two commercial finite element programs for solution of geotechnical problems (Phase2 and Plaxis 2D) since they use different techniques to simulate fractures in continuous media. In the stability analyses, the values of safety factors determined by the finite element method in 2D and 3D simulations were also compared with those calculated by the equilibrium method limit (method of slices). In general, it could be observed that the effects of discontinuities are larger on the horizontal displacement fields and they also tend to decrease the values of safety factors, even below the minimum thresholds recommended by Brazilian Standards.

The present document covers the studies over Structural Health Monitoring systems via vibration based methods. The topic is organized in two parallel studies. The first one analyzes the integrity of metal-composite single lap bonded joints. The second one approaches similar analyses for sandwich structures. The monitoring was made by investigating the dynamic response both computationally and experimentally to verify the reliability of applying vibration based SHM procedures, specifically with the objective of identifying the presence of debonding damage. The dynamic responses were obtained via accelerometers and piezoelectric sensors placed on top of the investigated structures (on the outward surface). The purpose for the accelerometers is to provide reference data for the analyses involving the piezoelectric sensors. Different metrics of damage identification were investigated, all working over a determined frequency range. They quantify the damage by analyzing either the magnitudes or phase angles of the dynamic responses among the undamaged and damage structures. This present work proposed modifications to some methodologies of damage quantification found in the literature and compared the results. The new metrics offered more reliable values for the damage quantification on several of the analyses. It was verified that the metrics are valid for the scenarios observed in the present study. The experimental analyses showed also the influence on the dynamic response due to the position of small elastomeric elements. In regards to the finite element analyses, the computational models showed similar results to the experimental data, the more accurate ones being the models for the bonded joints. For the computational models, improvements can be applied into the piezoelectric sensor (e.g. by using new finite element formulations), as well as the region of debonding (e.g. by using contact algorithms). It is important to highlight that the elastic properties of the skins for the sandwich structure were obtained by the literature, so the model can be improved in the future by applying properties obtained experimentally. / Esta dissertação aborda os estudos realizados no campo de Sistemas de Monitoramento da Integridade Estrutural por meio de métodos baseados em vibrações. O tópico abordado é organizado em dois estudos paralelos. O primeiro é relativo ao monitoramento da integridade de juntas coladas metal-compósito. O segundo versa sobre análises semelhantes em estruturas sanduíche. O monitoramento foi executado através das análises das assinaturas dinâmicas das estruturas, tanto computacionalmente quanto experimentalmente, visando avaliar a capacidade de metodologias vibracionais de SHM em detectar dano de descolamento. As respostas dinâmicas foram obtidas por meio de acelerômetros e sensores piezelétricos dispostos sobre a superfície das estruturas avaliadas. Os acelerômetros fornecem dados de referência para as análises realizadas com base nas respostas do sensor piezelétrico. Diferentes métricas de identificação de dano são abordadas, sendo que todas estão baseadas em análise no domínio da frequência, utilizando parâmetros de magnitude ou ângulo de fase das estruturas danificadas e intactas. O presente trabalho propôs alterações em algumas das metodologias encontradas na literatura e comparou os resultados das métricas originais com as modificadas. As métricas modificadas apresentaram resultados mais consistentes em vários cenários de análise. Constatou-se também que as métricas abordadas mostram-se válidas para os casos observados no presente estudo. As análises experimentais também evidenciaram a influência na assinatura dinâmica da estrutura sanduíche causada pelo posicionamento de pequenos elementos elastoméricos. Com relação às análises via elementos finitos, os modelos computacionais apresentaram resultados similares aos obtidos experimentalmente, sendo os da junta colada os mais precisos. Tais modelos computacionais podem ser melhorados no futuro por meio de uma modelagem mais detalhada dos elementos piezelétricos (por exemplo: por meio de novas formulações), como também da região de descolamento (por exemplo: por meio da implementação de algoritmos de contato). Deve-se ressaltar também que as propriedades elásticas das lâminas externas da estrutura sanduíche foram obtidas da literatura, assim sendo, o modelo poderá ser melhorado em estudos futuros por meio do emprego de propriedades obtidas experimentalmente.

The present document covers the studies over Structural Health Monitoring systems via vibration based methods. The topic is organized in two parallel studies. The first one analyzes the integrity of metal-composite single lap bonded joints. The second one approaches similar analyses for sandwich structures. The monitoring was made by investigating the dynamic response both computationally and experimentally to verify the reliability of applying vibration based SHM procedures, specifically with the objective of identifying the presence of debonding damage. The dynamic responses were obtained via accelerometers and piezoelectric sensors placed on top of the investigated structures (on the outward surface). The purpose for the accelerometers is to provide reference data for the analyses involving the piezoelectric sensors. Different metrics of damage identification were investigated, all working over a determined frequency range. They quantify the damage by analyzing either the magnitudes or phase angles of the dynamic responses among the undamaged and damage structures. This present work proposed modifications to some methodologies of damage quantification found in the literature and compared the results. The new metrics offered more reliable values for the damage quantification on several of the analyses. It was verified that the metrics are valid for the scenarios observed in the present study. The experimental analyses showed also the influence on the dynamic response due to the position of small elastomeric elements. In regards to the finite element analyses, the computational models showed similar results to the experimental data, the more accurate ones being the models for the bonded joints. For the computational models, improvements can be applied into the piezoelectric sensor (e.g. by using new finite element formulations), as well as the region of debonding (e.g. by using contact algorithms). It is important to highlight that the elastic properties of the skins for the sandwich structure were obtained by the literature, so the model can be improved in the future by applying properties obtained experimentally. / Esta dissertação aborda os estudos realizados no campo de Sistemas de Monitoramento da Integridade Estrutural por meio de métodos baseados em vibrações. O tópico abordado é organizado em dois estudos paralelos. O primeiro é relativo ao monitoramento da integridade de juntas coladas metal-compósito. O segundo versa sobre análises semelhantes em estruturas sanduíche. O monitoramento foi executado através das análises das assinaturas dinâmicas das estruturas, tanto computacionalmente quanto experimentalmente, visando avaliar a capacidade de metodologias vibracionais de SHM em detectar dano de descolamento. As respostas dinâmicas foram obtidas por meio de acelerômetros e sensores piezelétricos dispostos sobre a superfície das estruturas avaliadas. Os acelerômetros fornecem dados de referência para as análises realizadas com base nas respostas do sensor piezelétrico. Diferentes métricas de identificação de dano são abordadas, sendo que todas estão baseadas em análise no domínio da frequência, utilizando parâmetros de magnitude ou ângulo de fase das estruturas danificadas e intactas. O presente trabalho propôs alterações em algumas das metodologias encontradas na literatura e comparou os resultados das métricas originais com as modificadas. As métricas modificadas apresentaram resultados mais consistentes em vários cenários de análise. Constatou-se também que as métricas abordadas mostram-se válidas para os casos observados no presente estudo. As análises experimentais também evidenciaram a influência na assinatura dinâmica da estrutura sanduíche causada pelo posicionamento de pequenos elementos elastoméricos. Com relação às análises via elementos finitos, os modelos computacionais apresentaram resultados similares aos obtidos experimentalmente, sendo os da junta colada os mais precisos. Tais modelos computacionais podem ser melhorados no futuro por meio de uma modelagem mais detalhada dos elementos piezelétricos (por exemplo: por meio de novas formulações), como também da região de descolamento (por exemplo: por meio da implementação de algoritmos de contato). Deve-se ressaltar também que as propriedades elásticas das lâminas externas da estrutura sanduíche foram obtidas da literatura, assim sendo, o modelo poderá ser melhorado em estudos futuros por meio do emprego de propriedades obtidas experimentalmente.

Made available in DSpace on 2016-03-15T19:36:37Z (GMT). No. of bitstreams: 1 Kyosuke Siqueira Saito.pdf: 4273063 bytes, checksum: 72ef7d0c147daede5763573276e7efda (MD5) Previous issue date: 2013-02-15 / Universidade Presbiteriana Mackenzie / The development of new commercial vehicles have as one of its major goals increase the operational energetic efficiency or fuel consumption decrease. The vehicle´s mass reduction is one of the most direct ways to achieve this goal. The vehicle´s axles usually have its structure made of ferrous materials due to its high strength and low cost. Alternative materials with lower density and higher strength are continuosly researched and developed. Among these materials the aluminum compared with ferrous materials appears as an interesting alternative to replace ferrous alloys in some applications. The aluminum have its density significantly smaller than ferrous materials opening possibilities to significant mass reductions. In this study were performed an evaluation through the comparison of aluminum alloys and ferrous materials on different load conditions and were presented the replacement gains for each load situation. It was evaluated possibility to replace ferrous materials with aluminum alloys on commercial vehicles rear axle structures through finite element analysis as a step on a new product validation. The study results show that is possible to use the aluminum in commercial vehicle axles with mass reduction ranging from 1,1% to 61,0% without loss of structural properties. / O desenvolvimento de novos veículos comerciais tem como um de seus objetivos principais o aumento da eficiência energética operacional ou redução do consumo de combustível. A redução da massa dos veículos é uma das estratégias mais diretas para o alcance deste objetivo. Os eixos de veículos tradicionalmente têm sua estrutura feita de materiais ferrosos devido à sua alta resistência e baixo custo. Materiais alternativos de mais baixa densidade e alta resistência são pesquisados e desenvolvidos continuamente. Dentre esses materiais, o alumínio, comparado com materiais ferrosos tem-se mostrado uma alternativa interessante para a substituição de ligas ferrosas para algumas aplicações. O alumínio possui uma densidade muito inferior a dos ferrosos abrindo a possibilidade de ganhos significativos de massa. Neste estudo foi feito uma avaliação através da comparação entre ligas de alumínio e materiais ferrosos em diferentes condições de carregamento e apresentado os ganhos da substituição em cada condição de carregamento. Foi avaliada a possibilidade de substituir materiais ferrosos por ligas de alumínio na estrutura de eixos traseiros de veículos comerciais através de uma análise por elementos finitos como uma etapa da validação de um novo produto. Os resultados do estudo mostram que é possível usar o alumínio na estrutura de eixos de veículos comerciais com redução de massa variando de 1,1% a 61,0% sem perda de características estruturais.

O grande desafio da Implantodontia é alcançar resultados a longo prazo com maior preservação dos tecidos ósseos, resposta adequada dos tecidos conjuntivos e manutenção da estabilidade secundária adequada para a retenção de próteses. Estes fatores evitam a perda indesejável tanto do tratamento reabilitador quanto dos tecidos ósseos de suporte. A região extraoral apresenta menores espessuras ósseas em comparação às regiões de maxila e mandíbula, especialmente no osso temporal. Portanto, os seguintes aspectos foram investigados: (i) Análise pelo Método dos Elementos Finitos (FEA) de 16 modelos virtuais, com aplicação de forças estáticas de tensão e compressão nos pontos médios entre os implantes. Três implantes maxilofaciais extraorais foram posicionados no osso temporal, onde um deles foi posicionado sobre o processo mastóide. Este estudo foi totalmente realizado em ambiente computacional. Foram empregados dois tipos de conexões protéticas e intermediários retos de conicidades 20º e 45º, posicionados virtualmente no modelo de osso temporal, com paralelismo entre eles. Foi desenhada uma barra virtual para retenção protética do tipo barra-clipe da prótese auricular. Foram consideradas as melhores configurações aquelas apresentando distribuição uniforme e branda das tensões de von Mises sobre o tecido ósseo adjacente aos implantes. (ii) Confecção de corpos de prova com graus variáveis de pigmentação para (a) melhorar a reprodutibilidade da coloração (b) entender e reduzir o processo de descoloração para melhorar a longevidade das próteses. Um elastômero maxilofacial tipo A foi pigmentado intrinsecamente de acordo com os seis tons da Escala de Fitzpatrick. Uma técnica de pigmentação foi desenvolvida a partir dos resultados obtidos a partir de uma Escala de Fitzpatrick impressa em papel e dos pigmentos intrínsecos de cores primárias. Este dimetil-metilvinil-siloxano reforçado por platina A 223-30 (Factor II, Inc., Lakeside, AZ, USA) apresenta dureza \"Shore-A\" 30. As amostras foram expostas a fotoenvelhecimento acelerado, e sua degradação mapeada com Espectroscopia UV/Vis/NIR. Concluiu-se que: (i) Os implantes com conexão cone Morse plataforma 3.7 tem melhor comportamento biomecânico com intermediários de 45o e altura de 2mm. Sugere-se planejamento cirúrgico visando a instalação a 3 horas para o temporal esquerdo e 9 horas para o temporal direito, mais 6 horas (mastóide). Implantes com conexão cone Morse plataforma 4.0 apresentaram comportamento biomecânico desejável com intermediários de 20o e alturas de 2mm or 4mm. Para implantes com conexão cone Morse plataforma 4.0, sugere-se a instalação a 6-9-12 horas para o temporal direito, e 12-6-3 para o esquerdo, visando comportamento biomecânico adequado. Sugere-se que os implantes extraorais Brånemark hexágono externo com plataforma 4.1 regular ou expandida sejam preferencialmente empregados com intermediários de 20o. (ii) O SiO2 5% pode ser adicionado à preparação do silicone para retardar o desbotamento da prótese maxilofacial. O TiO2 traz mudanças visuais significativas e pode ser considerado como opacificador. / Major challenges in Implantology include: achieving longevity of implants, bone tissue preservation, connective tissue suitable answer and maintenance of secondary stability in order to retain prosthesis. These factors avoid the undesirable loss of both rehabilitation treatment and supporting bone tissues. The extraoral region has less bone depth compared to the maxilla and mandible regions, especially for the temporal bone. Therefore, the following aspects were investigated: (i) Finite Elements Analysis (FEA) of 16 virtual models, with static application of tension and compression forces in medium points between implants. Three extraoral maxillofacial implants were placed on the temporal bone, which one of them was placed on the mastoid process. This study was made entirely in a computational environment. Two prosthetic connection types and straight Intermediários were employed, with conicities of 20º and 45º, placed virtually on the temporal bone model, mutually parallel. A virtual bar for bar-clip prosthetic retention of auricular prosthesis was designed. The best configurations were considered to be the ones presenting uniform and mild von Mises tension distribution over the bone tissue around the implants. (ii) Generation of samples with varying degree of pigmentation to (a) improve the reproducibility of the colouration (b) understand and minimise the discolouration process to improve prosthetics longevity. A maxillofacial elastomer type A was intrinsically pigmented according to the six tones of the Fitzpatrick Scale. A pigmentation technique was developed from spectroscopy outcomes of paper printed Fitzpatrick Scale and the primary colors pigments. This platinum reinforced dimethyl methylvinyl siloxane A 223-30 (Factor II, Inc., Lakeside, AZ, USA) presents \"Shore-A\" hardness 30. The samples were exposed to accelerated photo aging, and their degradation mapped with UV/Vis/NIR Spectroscopy. The effects of exclusion of oxygen and inclusion of nanoparticle fillers during prosthetic formulation were investigated. It was concluded that: (i) Morse taper prosthetic connection 3.7 platform implants, should be employed with 45o abutments with 2mm height. The surgical planning shall be for placement 3 hours for the left temporal bone and 9 hours for the right, and in 6 hours (mastoid). Morse taper prosthetic connection 4.0 platform implants behaved biomechanically desirably with 20o abutments in 2mm or 4mm heights. For the Morse taper connection 4.0 platform implants, their placement shall be in 6-9-12 hours, for the right temporal, and 12-3-6, for the left temporal, in order to achieve proper biomechanical behaviour. The Brånemark extraoral external hexagon implant, with 4.1 platform (normal or expanded) should preferrably be used with 20o abutments. (ii) The SiO2 5% may be added to the silicone preparation in order to slow maxillofacial prosthesis colour fading. The TiO2 brings visually significant changes and may be considered as an opacifier.

This thesis is on fatigue crack growth experiments and assessments of fatigue crack growth rates. Both constant and variable amplitude loads in two different materials are considered; a nickel based super-alloy Inconel 718 and a stainless steel 316L. The considered load levels extend from small scale yielding (SSY) to large scale yielding (LSY) for both materials. The effect of different load schemes on the fatigue crack growth rates is investigated on Inconel 718 and compact tension specimens in Paper A. It is concluded that load decreasing schemes give a to high Paris law exponent compared to constant or increasing load amplitude schemes. Inconel 718 is further analyzed in Paper B where growth rates at variable amplitude loading in notched tensile specimens are assessed. The predictions are based on the fatigue crack growth parameters obtained in Paper A. The crack closure levels are taken into consideration and it is concluded that linear elastic fracture mechanics is incapable of predicting the growth rates in notches that experience large plastic cyclic strains. Even if crack closure free fatigue parameters are used and residual stresses due to plasticity are included. It is also concluded that crack closure free and nominal fatigue crack growth data predict the growth rates equally well. However, if the crack closure free parameters are used, then it is possible to make a statement in advance on the prediction in relation to the experimental outcome. This is not possible with nominal fatigue crack growth parameters. The last three papers consider fatigue crack growth in stainless steel 316L. Here the load is defined as the crack tip opening displacement parameter. Paper C constitutes an investigation on the effect of plastic deformation on the potential drop and consequently the measured crack length. It is concluded that the nominal calibration equation obtained in the undeformed geometry can be used at large plastic deformations. However, two conditions must be met: the reference potential must be taken in the deformed geometry and the reference potential needs to be adjusted at every major change of plastic deformation. The potential drop technique is further used in Paper D and Paper E for crack length measurements at monotonic LSY. Constant amplitude loads are considered in Paper D and two different variable amplitude block loads are investigated in Paper E. The crack tip opening displacement is concluded in Paper D to be an objective parameter able to characterize the load state in two different geometries and at the present load levels. Furthermore, if the crack tip opening displacement is controlled in an experiment and the local load ratio set to zero, then only monotonic LSY will appear due to extensive isotropic hardening, i.e. elastic shake-down. This is also the reason why the linear elastic stress-intensity factor successfully could merge all growth rates, extending from SSY to monotonic LSY along a single line in a Paris law type of diagram, even though the generally accepted criteria for SSY is never fulfilled. For the variable amplitude loads investigated in Paper E, the effect of plastic deformation on measured potential drop is more pronounced. However, also here both the crack tip opening displacement parameter and the linear elastic stress-intensity factor successfully characterized the load state. / <p>QC 20130108</p>