Die vorliegende Arbeit umfasst die Entwicklung und Implementierung eines nichtlokalen duktilen Schädigungsmodells, die Anwendung von Verfahren zur Bestimmung von Materialparametern aus Versuchsdaten sowie die Berechnung von bruchmechanischen Kennwerten im spröd-duktilen Übergangsbereich durch die numerische Simulation von Bruchmechanikversuchen unter Verwendung der ermittelten Parameter. Das entwickelte nichtlokale duktile Schädigungsmodell basiert auf dem Modell nach Gurson-Tvergaard-Needleman (GTN). Durch die Einführung eines zusätzlichen Längenparameters mittels einer impliziten Gradientenformulierung wird die Netzabhängigkeit des GTN-Modells eliminiert. Zur Lösung des nunmehr gekoppelten Feldproblems wird das nichtlokale Schädigungsmodell in Form eines benutzerdefinierten Elements in ein Finite-Elemente-Programm implementiert. Zur Parameterbestimmung werden Kraft-Verschiebungs-Kurven des Small-Punch-Tests (SPT), einem Kleinstprobenversuch, ausgewertet. Aufgrund des sehr geringen Materialbedarfs für die Herstellung der benötigten SPT-Proben werden Rest- bzw. Bruchstücke von Charpy-Tests weiterverwendet. Es werden zwei ferritische Reaktorstähle im bestrahlten und unbestrahlten Zustand untersucht. Die Versuchsreihen decken den vollständigen Bereich der Zähigkeit beider Stähle ab. Die Bestimmung von Bruchzähigkeiten erfolgt nach dem Konzept des Local Approach allein durch numerische Berechnung des Spannungs- und Verformungszustandes in Bruchmechanikproben. Hierbei werden die zuvor aus dem SPT bestimmten Fließkurven und Schädigungsparameter verwendet. Die berechneten Bruchzähigkeiten werden mit experimentellen Ergebnissen verglichen. / This work comprises the development and implementation of a non-local ductile damage model, the application of methods for the identification of material parameters from experimental data as well as the calculation of fracture mechanics parameters in the brittle-ductile transition zone through numerical simulations of fracture mechanical tests using the identified parameters. The developed non-local ductile damage model is based on the Gurson-Tvergaard-Needleman model (GTN). The pathological mesh sensitivity of the GTN model is eliminated by introducing an additional length parameter by means of an implicit gradient formulation. To solve the coupled field problem, the non-local damage model is implemented in a finite element program in the form of a userdefined element. Force-displacement-curves of the small punch test (SPT), a miniaturised test, are evaluated for the determination of material parameters. Given the modest material requirements for the preparation of the required samples remnants of Charpy-specimens are reused. Two ferritic reactor steels, both irradiated and unirradiated, are examined. The experiments cover the full brittle-ductile transition region of the steels. Following the concept of the Local Approach, fracture toughness values are determined by numerical calculation of the stress and deformation state in fracture mechanics specimen only. Here, the yield curves and damage parameters previously determined from the SPT are used. The calculated fracture toughness values are compared with experimental results.

Os avanços na utilização do concreto reforçado com fibras (CRF) para fins estruturais trazem cada vez mais a necessidade de se desenvolver ensaios práticos que possam controlar o material, analisando a capacidade resistente residual do compósito para diferentes níveis de abertura de fissura. O ensaio de duplo puncionamento (EDP) é uma promissora alternativa nesta direção, uma vez que haja uma correlação já comprovada com outros métodos de ensaio bem estabelecidos. Este trabalho objetivou investigar a repetibilidade e reprodutibilidade do EDP, considerando os parâmetros de cargas de fissura da matriz cimentícia e cargas residuais, verificando se existe igualdade de médias e igualdade de variâncias nas diferentes situações criadas, para 95% de confiabilidade. A repetibilidade foi avaliada por meio de um programa experimental, com moldagem dos corpos de prova no Centro de Pesquisa e Desenvolvimento da Construção Civil - CPqDCC, da Escola Politécnica da Universidade de São Paulo, envolvendo dois teores de fibra de aço com ancoragem em gancho (30 kg/m³ e 55 kg/m³) em três séries iguais de moldagem. A reprodutibilidade foi avaliada em um programa interlaboratorial, com participação de 6 laboratórios independentes e empregando a mesma fibra e teores. Como ferramentas para comparação dos resultados e avaliar se houve repetição e reprodução dos parâmetros do ensaio, foi utilizada análise de variância (ANOVA) e a metodologia da ASTM E691. Os resultados mostraram que foi possível obter repetibilidade e reprodutibilidade de médias para os parâmetros de cargas residuais com um número limitado de corpos de prova. No entanto, as variâncias são mais sensíveis que as médias, e não mostraram repetição total quando a homogeneização das fibras no volume total do concreto é prejudicada. Ainda, as cargas de fissuração do ensaio (Pf) não se mostraram totalmente repetíveis e nem reprodutíveis, pois podem ser afetadas pela máquina de ensaio e operador. / The advances in the use of fiber reinforced concrete (CRF) for structural applications bring the need to develop more practical tests to control the FRC by analyzing the residual strength of the composite for different crack openings levels. The double punch test (DPT) is a promising alternative in that sense, once a correlation with already proven test methods is achievable. This work aimed to investigate the repeatability and reproducibility of the DPT, considering the parameters of crack load and residual loads, verifying if there is equality of means and equality of variances in the different situations created, for 95% reliability. The repeatability was evaluated by an experimental program, with the specimens molding at the Research and Development Center in Civil Construction - CPqDCC, at the Polytechnic School of the University of São Paulo, involving two hooked end steel fiber contents (30 kg/m³ and 55 kg / m³), in three equal molding series. The reproducibility was evaluated in an interlaboratory program, with the participation of six independent laboratories, and using the same fiber and contents. The analysis of variance (ANOVA) and the ASTM E691 methodology were applied as a tool to compare the results and to evaluate if there were repetition and reproduction of the test parameters occurred. Together with these tools, an inductive test was used on the reproducibility specimens to verify the scatter of the fiber among them. The results showed that it was possible to obtain repeatability and reproducibility of means for the parameters related to the residual loads. However, the variances are more sensitive than the means, and did not show total repetition when the homogenization of the fibers in the total volume of the concrete is compromised. Moreover, the cracking loads of the test (Pf) were not totally repeatable and reproducible, as they can be affected by the testing machine.

In this thesis, the relationship between the elastic modulus of PDMS and the base/agent ratio (the amount of crosslinking) is studied. Reliable macroscopic compression test instrument was developed. Preload method was applied for the nanoindentation flat punch test to develop full contact. In chapter 2, an easy instrument setup for macroscopic compression test is described. A series of PDMS samples with different base/agent ratios were tested using the macroscopic compression method. The relationship between PDMS elastic modulus and its base/agent ratio was established. In chapter 3, PDMS nanoindentation DMA tests provide stable data with different test control models. The storage modulus collected using nanoindenting DMA tests is comparable with elastic modulus collected in PDMS compression test in chapter 2. Nanoindentation experiments with flat punch were also done to test the elastic modulus of PDMS network 5:1. The adhesion force tests with different nanoindentation tips, which are Berkovich tip, conical tip and cube corner tip, show that PDMS's adhesion force is related to the sample's base/agent ratio, the nanoindentating depth and the tip's geometrical shape.

The objective of this study is to develop test protocols for comparing the effectiveness of fiber-reinforced concrete (FRC) mixtures with high-performance steel fibers. Steel fibers can be added to fresh concrete to increase the tensile strength, ductility, and durability of concrete structures. In order to quantify steel fiber-reinforced concrete (SFRC) mixtures for field applications, a material test capable of predicting the performance of SFRC for field loading conditions is required. However, current test methods used to evaluate the structural properties of FRC (such as residual strength and toughness) are widely regarded as inadequate; a simple, accurate, and consistent test method is needed. It was determined that the Double-Punch Test (DPT), originally introduced by Chen in 1970 for plain concrete, could be extended to fiber-reinforced concrete to satisfy this industry need. In the DPT, a concrete cylinder is placed vertically between the loading platens of the test machine and compressed by two steel punches located concentrically on the top and bottom surfaces of the cylinder. It is hypothesized that the Double-Punch Test is capable of comparing future fiber-reinforcement design options for use in structural applications, and is suitable for evaluating FRC in general. The DPT Research and Testing Program was administered to produce sufficient within-laboratory data to make conclusions and recommendations regarding the simplicity, reliability, and reproducibility of the DPT for evaluating the performance of SFRC. Several variables (including fiber manufacturer, fiber content, and testing equipment) were evaluated to verify the relevance of the DPT for FRC. In this thesis, the results of 120 Double-Punch Tests are summarized and protocols for its effective application to fiber-reinforced concrete are recommended. Also, fundamental data is provided that indicates the DPT could be standardized by national and international agencies, such as the American Society of Testing and Materials (ASTM), as a method to evaluate the mechanical behavior of FRC. This project is sponsored by the Texas Department of Transportation (TxDOT) through TxDOT Project 6348, "Controlling Cracking in Prestressed Concrete Panels and Optimizing Bridge Deck Reinforcing Steel," which is aimed at improving bridge deck construction through developments in design details, durability, and quality control procedures. / text

Submitted by Marlene Santos (marlene.bc.ufg@gmail.com) on 2017-10-18T18:04:12Z No. of bitstreams: 2 Dissertação - Ana Carolina Barros da Rosa Pedroso - 2017.pdf: 4185666 bytes, checksum: 974e13fd85577c264019ad51d76003b6 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2017-10-19T10:29:32Z (GMT) No. of bitstreams: 2 Dissertação - Ana Carolina Barros da Rosa Pedroso - 2017.pdf: 4185666 bytes, checksum: 974e13fd85577c264019ad51d76003b6 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2017-10-19T10:29:32Z (GMT). No. of bitstreams: 2 Dissertação - Ana Carolina Barros da Rosa Pedroso - 2017.pdf: 4185666 bytes, checksum: 974e13fd85577c264019ad51d76003b6 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2017-08-30 / The economic relevance of equine breeding in Brazil indicates the importance of the development of new economically viable treatments to promote tissue healing. Skin grafts and Platelet Rich Plasma (PRP) are available alternatives for improving the wound healing process in these animals. This study aimed to establish a simple method for autologous PRP production, as well as to evaluate its action on cutaneous wounds containing skin autografts in horses. Eight healthy horses were used, ranging in age from 3 to 18 years and mean live weight of 350 kg. For PRP obtention, a double centrifugation protocol was used. Two 6 x 6 cm wounds were performed on each side of the gluteal region. After the wound was filled by granulation tissue, punch autografts were obtained, with fragments harvested from the neck. Left-sided wounds were treated with PRP (GT) and right-sided wounds were not treated (GC). The protocol used to obtain PRP resulted in platelet concentration, on average, three times higher than that of whole blood. In the evaluation of PRP action in the healing of autografts, macroscopic and microscopic variables were considered. There was no significant difference between the groups (p> 0.05) for the variables inflammatory infiltrate, young fibroblasts, collagenization, epidermal thickness, macroscopic and microscopic integration of the autografts and retraction of the wound edges. However, neovascularization was significantly greater (p = 0.0191) in the PRP group, on the 14 th day after insertion of the autografts. It is concluded that the double centrifugation method results in PRP with adequate platelet concentration for therapeutic use. As for the action of PRP, this favors the process of skin repair with autografts in horses, since it increases the neovascularization in the initial phase of wound healing. Moreover, PRP seems to positively influence the integration of skin autografts and retraction of the wound edges, which is of fundamental importance for the reduction of hospitalization time and consequently of the therapeutic costs. / A relevância econômica da criação de equinos no Brasil denota a importância do desenvolvimento de novos tratamentos, economicamente viáveis, para promover a cicatrização tecidual. Os enxertos de pele e o Plasma Rico em Plaquetas (PRP) são alternativas disponíveis para a melhoria do processo de cicatrização nesses animais. Este estudo teve por objetivo estabelecer um método simples para produção de PRP autólogo, assim como avaliar sua ação sobre feridas cutâneas contendo autoenxertos de pele em equinos. Foram utilizados oito equinos hígidos, com idade variando entre três e 18 anos e peso vivo médio de 350 kg. Na obtenção do PRP, foi utilizado protocolo em dupla centrifugação. Foram realizadas duas feridas de 6 x 6 cm, em cada um dos lados da região glútea. Após o preenchimento da ferida por tecido de granulação, foram realizados autoenxertos do tipo punch, com fragmentos colhidos do pescoço. As feridas do lado esquerdo receberam tratamento com PRP (GT) e as feridas do lado direito não receberam tratamento (GC). O protocolo utilizado na obtenção do PRP resultou em concentração plaquetária, em média, três vezes acima daquela do sangue total. Na avaliação da ação do PRP na cicatrização dos autoenxertos, foram consideradas variáveis macroscópicas e microscópicas. Não houve diferença significativa entre os grupos (p>0,05) quanto às variáveis infiltrado inflamatório, fibroblastos jovens, colagenização, espessura da epiderme, integração macroscópica e microscópica dos autoenxertos e retração das bordas da ferida. Contudo, a neovascularização foi significativamente maior (p=0,0191) no grupo tratado com o PRP, no 14º dia após a inserção dos autoenxertos. Conclui-se que o método de dupla centrifugação resulta em PRP com concentração plaquetária adequada ao uso terapêutico. Quanto à ação do PRP, este favorece o processo de reparo da pele com autoenxertos em equinos, já que aumenta a neovascularização na fase inicial da cicatrização da ferida. Ainda, o PRP parece influenciar positivamente a integração dos autoenxertos de pele e a retração das bordas da ferida, o que é de fundamental importância para a redução do tempo de internação dos animais e, consequentemente, dos custos terapêuticos.

This diploma thesis view to problem electrical discharge sinking. Forth with deal production of indexable insert cemented carbide and application electrical discharge sinking at this technology.

SKLENÁŘ Luděk: Bulk forming technology of grooved charge. The project prepared as part of the Master-degree studies in the Manufacturing Technology and Management in Industry, concerns the technology design for manufacturing a grooved charge by cold bulk forming. Grade 12 040.3 (CSN) steel was used as the initial material. For the batch of 50,000 pieces per year are proposed three alternatives. The chosen option No. 1 is made of technology and tensile strength calculations for metal forming operations: upsetting, backwards extrusion, forward extrusion and calibrating. The grooved charge production is designed for two forming processes that will be realised at the Colombo press Agostino, which is part of the machinery park company Metaldyne Oslavany. The extruding dies for the manufacture are made of tool steel 19 655 and tool steel 19 830 is designed for extruding punches.

The project developed as a part of continuing master’s program in the field of M-STG Mechanical engineering technologies introduces a technological proposal of producing a side panel of computer case. Based on the research of published studies on the topic of surface forming and methods of production of shape openings in sheet-metal, we chose the variant of production of parts using punch press and press brake and selected appropriate material – steel with protective zinc and aluminum coating. Based on the research of published studies on the topic of computer cases we processed analyses of shape designs and chose optimal variant, for which we prepared calculations of production costs in comparison with other proposals.

Title: Acute effect of a warm-up on the force of a punch Objectives: The aim of this diploma thesis is to test whether a warm-up before a performance affects the force of a punch at a sample participants practicing full-contact combat sports. Further goal is to analyze a change in the force of a punch depending on elapsed time after warming up. Methods: Each participant in this experimental study with intra-subject design went through all phases of the measurement, where the force of a punch was tested in four specified times (before a warm-up and then 4, 10 and 25 minutes after the warm-up). Results: No statistically significant effect of a warm-up on the force of a punch was observed, nor was there a statistically significant change in the force of a punch during the time following a warm-up. However, a warm-up did have a significant effect on change in heart rate and body temperature. Keywords: Combat sports, performance, fight, dynamic stretching, explosive power, punch sensor

Title: Analysis and comparison of boxing styles of elite amateur boxers from Cuba and Kazakhstan Objectives: The main goal of this thesis was to find out whether the frequency of use of punching techniques and the distance from which these punching techniques are used are statistically significant for the style of two the most successful countries in amateur boxing. The countries were compared in the use and success of the strikes and compared to their preference for long or medium combat distance. Methods: The method of quantitative observation was used, in which data was obtained by watching video recordings. Part of the matches was evaluated by recording the results manually on paper, the other part in the BORIS program. All data was then transcribed into a Microsoft Excel spreadsheet, where it was also processed. The source for the data were publicly available video recordings from top competitions in 2010-2020. Results: Differences between countries in the monitored indicators are insignificant and boxing styles do not differ much. In the frequency of the use of striking techniques between the rounds, a significant difference was found only between the first and second round of the Kazakhs. In the case of determining the preference for long and medium distance combat between the rounds, there...