The aim of this diploma thesis is processing the new technology of production single parts from metal plate „ Vanečka", which produced is yearly set 50000 pieces. Component of made in steel S235JRG1 (ČSN 41 1373) thickness 3 and 5 mm. Based on literary search rolling cutting and bending are designed two variants of production. Both variants use for cut - out cloak and face rolling cutting close - set on press LEN 63C. Different operation is bending. First variant includes bending in the bending tool, the other on press brake. Both variants is processed economics revaluation and consequently intended transition points.

This thesis presents the development and implementation of a generalized optimization framework for use in sheet-stamping process simulation by finite element analysis. The generic framework consists of three main elements: a process simulation program, an optimization code, and a response filtering program. These elements can be filled by any combination of applicable software packages. Example sheet-stamping process simulations are presented to demonstrate the usage of the framework in various forming scenarios. Each of the example simulations is presented with a sensitivity analysis. These examples include analysis of a 2-dimensional single-stage forming, a 2-dimensional multi-stage forming, and two different 3-dimensional single-stage forming processes. A forming limit diagram is used to define failure in the 3-dimensional process simulations. Optimization results are presented using damage minimization, thinning minimization, and springback minimization with aluminum alloy 6061-T6 blanks.

No description available.

La miniaturisation des composants est aujourd’hui un challenge mondial. La fabrication de ces composants est rendue difficile par un certain nombre de phénomènes liés aux effets d’échelle. Il est ainsi nécessaire de répondre à ces contraintes de réduction d’échelle en termes de conception, de réalisation et de fonctionnement de ces systèmes. Cette étude aborde la problématique de la miniaturisation des procédés et plus particulièrement du procédé de micro-formage incrémental « mono-point » (micro-SPIF) à travers des études expérimentales et numériques. Le micro-formage incrémental de tôles est présenté comme une approche intéres sante de fabrication de structures minces. La géométrie désirée est assurée par la trajectoire d’un outil imposant une déformation locale sur la tôle serrée en son contour. Dans un premier temps, une approcheexpérimentale consistant à analyser le comportement mécanique des éprouvettes en alliage de cuivre avec différentes tailles de grains par des essais de traction a été proposée. L’interaction entre la géométrie et la microstructure est évaluée à l’aide du ratio de l'épaisseur par la taille moyenne de grains Φ=t/d. Un pilote de formage incrémental « mono-point » instrumenté a été également développé. Une campagne d'essais expérimentaux de micro-SPIF a été ainsi réalisée sur des flans par différentes tailles de grains afin d'étudier les effets de la microstructure sur la géométrie, l’état de surface, la distribution des épaisseurs et sur l’évolution des efforts. Dans un second temps, un modèle paramétrique de type éléments finis simulant le micro-SPIF a été développé en langage MATLAB®. Le code de calculs LS-DYNA® a été utilisé pour simuler le procédé en adaptant une loi de comportement élastoplastique. Ensuite, les résultats obtenus en termes de géométrie,d’évolution de l’épaisseur et d’efforts de formage sont confrontés aux relevés expérimentaux afin de valider la procédure numérique. Dans un troisième temps, une loi élastoplastique endommageable décrivant les principaux phénomènes physiques intervenant durant le formage des métaux en grandes déformations a été présentée. Une procédure d'identification de cette loi basée sur une analyse inverse de l’effort au cours du procédé de micro-SPIF a été proposée et des tests de validation du modèle ont été discutés. Enfin, une analyse de l'identifiabilité locale basée sur un indice de multicolinéarité des fonctions de sensibilité est effectuée pour valider la procédure d’identification paramétrique et quantifier l’intérêt du procédé pour la caractérisation quantitative des tôlesminces en très grandes déformations / The miniaturization of components is now a world challenge. The manufacture of these componentsis difficult because of several phenomena related to the so-called size effect. It is thus necessary to fulfill theserequirements of scaling down in terms of design, implementation and operations. This study deals with theproblems of miniaturization processes, especially the “micro-Single Point" Incremental Forming process (micro-SPIF) through experimental and numerical studies. Micro-single point incremental forming process is presentedas an interesting approach for thin structures manufacturing. The desired geometry is provided by the tool pathrequiring a local deformation in a sheet clamped along its contour. Firstly, an experimental approach consistingin analyzing the mechanical behaviour of copper alloy specimens with various grain sizes by tensile tests hasbeen proposed. The interaction between the geometry and the microstructure is evaluated using the ratio of thethickness by the average grain size Φ=t/d. An instrumented micro-SPIF device was also developed. A set ofsingle point incremental sheet forming experimental tests were conducted on blanks with several grain sizesusing two forming strategies in order to study the effect of microstructure on the geometry, the surface topology,the thickness distribution and the forming forces evolutions. Secondly, a finite element parametric model capableof simulating the micro-SPIF process was developed in MATLAB® language. The commercial LS-DYNA® codewas used to simulate this process using an elastic-plastic constitutive law. Then, the results obtained in terms ofgeometry, thickness evolution and forming forces are compared with the experimental results in order to validatethe numerical procedure. Thirdly, an elastic-plastic damage model describing the main physical phenomenainvolved during metal forming by large deformation was presented. An identification procedure of thisbehaviour law based on the inverse analysis of the axial forming force during micro-SPIF process was proposedand several validation tests of the model were discussed. Finally, local identifiability analysis based on an indexof multicollinearity of the sensitivity functions was performed in order to validate the parameters identificationprocedure and quantify the advantage of the process for quantitative mechanical behaviour characterization ofthin metal sheets at large strains

Incremental sheet forming (ISF) is a novel metal shaping technology that is economically viable for low-volume manufacturing, customisation and rapid-prototyping. It uses a small tool that is controlled by a computer-numerically controlled sequence and the path taken by this tool over the sheet defines the product geometry. Little is currently known about how to design the tool-path to minimise geometric errors in the formed part. The work here addresses this problem by developing a model based tool-path optimisation scheme for ISF. The key issue is how to generate an efficient model for ISF to use within a path optimisation routine, since current simulation methods are too slow. A proportion of this thesis is dedicated to evaluating the applicability of the rigid plastic assumption for this purpose. Three numerical models have been produced: one based on small strain deformation, one based on limit analysis theory and another that approximates the sheet to a network of rods. All three models are formulated and solved as second-order cone programs (SOCP) and the limit analysis based model is the first demonstration of an upper-bound shell finite element (FE) problem solved as an SOCP. The models are significantly faster than commercially available FE software and simulations are compared with experimental and numerical data, from which it is shown the rigid plastic assumption is suitable for modelling deformation in ISF. The numerical models are still too slow for the path optimisation scheme, so a novel linearised model based on the concept of spatial impulse responses is also formulated and used in an optimal control based tool-path optimisation scheme for producing axisymmetric products with ISF. Off-line and on-line versions of the scheme are implemented on an ISF machine and it is shown that geometric errors are significantly reduced when using the proposed method. This work provides a new structured framework for tool-path design in ISF and it is also a novel use of feedback to compensate for geometrical errors in ISF.

A estampagem incremental é um processo de deformação incremental de chapa que pode ser classificado em três modos distintos: estampagem incremental sem matriz, estampagem incremental com matriz parcial e estampagem com matriz total. A deformação ocorre devido ao contato entre a ferramenta e a chapa, localmente e progressivamente, ao longo de uma trajetória pré-definida. A chapa permanece presa a suportes que fixam as suas extremidades de maneira a impedir os deslocamentos provocados pela passagem da ferramenta. A primeira parte deste trabalho compreende estudos em elementos finitos, usando o software LS-Dyna, sobre a trajetória das deformações na estampagem incremental para a fabricação de flanges em chapas previamente furadas de liga de alumínio AA1050. Foram realizados testes de contato e de linha que permitiram definir parâmetros da simulação. Os resultados para as deformações foram confrontados com os resultados obtidos experimentalmente por outros autores e permitiram verificar o comportamento das deformações nos flanges. As deformações crescem montonicamente até os valores máximos. Este resultado confirma a teoria de que na estampagem incremental de chapas a fratura ocorre sem o prévio aparecimento da estricção. A segunda parte deste trabalho trata do desenvolvimento de um suporte modular aplicável a estampagem incremental, tanto na sua variante sem matriz quanto com matriz, com o intuito de aumentar a flexibilidade do processo com relação à geometria da peça a ser deformada. Foi empregada a técnica de análise de valor objetivando alcançar a melhor funcionalidade do sistema. Como resultado foi obtido um suporte modular que atende os requisitos de rigidez, flexibilidade, modularidade, agilidade na troca da chapa a ser deformada e simplicidade construtiva. / The sheet incremental forming can be classified into three basic configurations, depending on the number of contact points between the sheet, tool and die (when present). Single incremental forming (absence of specific dies) and two point incremental forming (presence of a partial or full die) can be distinguished. The process makes use of a simple, low-cost, hemispherical tipped tool to precisely and progressively shape a blank into a metal sheet along a predefined tool path. The sheet is fixed onto the rig to prevent lateral displacements caused by tool movement. The first part of this work includes studies about finite elements, using the LS-Dyna software, applied to deformation path in hole-flanging produced by incremental sheet forming. The investigation was carried out using aluminum alloy AA1050. Contact and line numerical results support simulation parameters choices. The results from the strains were compared with empirical ones obtained by other authors. The results showed the deformation mechanics behavior of the hole-flanging. The strain paths of hole-flanging produced by incremental sheet forming grew linearly and monotonically from the origin to the maximum achievable strains. This result confirms the absence of local necking along plane strain directions. The second part of this work deals with the development of a modular rig that can be applied to dieless, partial or total die single point incremental forming in order to increase the flexibility of the process concerning the geometry of the part to be deformed. The result was a modular rig with constructive simplicity and requirements of stiffness, flexibility and modularity when exchanging sheets.

Este trabalho apresenta um modelo inovador de coletor solar plano, com placa absorvedora fabricada por Estampagem Incremental e Soldagem FSW (Friction Stir Welding). Esta placa absorvedora é constituída de duas chapas de alumínio AA1200-H14 com espessura de 1 mm, estampadas e soldadas em simetria, a fim de que na união das chapas sejam deixados canais para passagem de água. Neste estudo foi realizada a caracterização do material por Ensaio de Tração e Ensaio Nakajima. Para determinação dos parâmetros de Estampagem Incremental foram realizados 16 experimentos com ferramenta de diâmetro df = 9,5 mm, variando a rotação de N = 50 rpm a 800 rpm e o incremento vertical de Δz = 2 mm a 0,2 mm, mantendo o avanço em = 250 mm/min. E também foram realizados 3 experimentos com ferramenta df = 22 mm, variando o incremento vertical de Δz = 2 mm a 0,5 mm, mantendo a rotação em N = 50 rpm e o avanço em = 250 mm/min. Para determinação dos parâmetros de Soldagem FSW foram realizados 4 experimentos com ferramenta de ombro de diâmetro 8 mm e pino roscado M3x0,5, mantendo a rotação em N = 1500 rpm e variando o avanço entre = 100 mm/min a 400 mm/min. Em seguida foi fabricado um protótipo de placa absorvedora de coletor solar com área de 0,12 m². Nos experimentos realizados foi constatado que é possível obter maiores deformações na Estampagem Incremental do que na Estampagem Convencional e que as deformações são mais elevadas quando se utiliza menores diâmetros, maiores rotações e menores incrementos verticais da ferramenta. Na Soldagem FSW não foi constatada influência na qualidade do cordão de solda em relação à variação do avanço da ferramenta. Neste estudo também se verificou que é possível fabricar protótipos de placas absorvedoras de coletores solares pelos processos de Estampagem Incremental e Soldagem FSW. No entanto, para coletores em tamanho comercial, novos estudos são necessários para melhorar a forma de fixação das chapas durante a Soldagem FSW. / This work presents an innovative model of flat plate solar collector, with absorber plate manufactured using Incremental Sheet Forming (ISF) and Friction Stir Welding (FSW). This absorber plate consists of two AA1200-H14 aluminum sheets with a thickness of 1 mm, stamped and welded in symmetry, in order to leave channels for the passage of water. In this study the characterization of the material by Nakajima Test and Traction Test was performed. In order to determine the parameters of ISF, 16 experiments were performed with a tool of diameter df = 9.5 mm, varying the rotation speed of N = 50 rpm at 800 rpm and the step down of Δz = 2 mm to 0.2 mm, maintaining the feed rate at = 250 mm/min. Also, 3 experiments with tool df = 22 mm were performed, varying the step down of Δz = 2 mm to 0.5 mm, maintaining the rotation speed at N = 50 rpm and the feed rate at = 250 mm/min. For determination of FSW parameters, 4 experiments with 8 mm diameter shoulder tool and M3x0.5 pin were performed, maintaining the rotation speed at N = 1500 rpm and varying the feed rate from = 100 mm/min to 400 mm/min. A prototype solar collector absorber plate with a 0.12 m² area was then manufactured. In the experiments carried out, it was found that it is possible to obtain greater deformations in the ISF than in the Conventional Stamping and that the deformations are higher when using smaller diameters, higher rotations and smaller step downs of the tool. In FSW, no influence was observed in the quality of the weld bead in relation to the variation of the tool feed rate. In this study it was also verified that it is possible to manufacture prototypes of solar collector absorber plates by the processes of ISF and FSW. However, for commercial size collectors, further studies are needed to improve the way the plates are fixed during FSW.

O presente trabalho investiga o comportamento da chapa de latão C268, com 0,50 mm de espessura, quando exposto ao processo de Estampagem Incremental de Chapas de Metal (Incremental Sheet Metal Forming -ISMF). Especificamente para a pesquisa, foram utilizadas as modalidades de Estampagem Incremental com Ponto Simples (Single Point Incremental Forming- SPIF) e Estampagem Incremental de Múltiplos Passes (Multi Pass Single Point Incremental Forming- MSPIF). Os experimentos foram baseados em uma geometria de tronco de pirâmide de base quadrada com 100 mm de lado e 45 mm de profundidade. Para as estratégias de estampagem foi atribuído, a estampagem helicoidal. Como resultado principal, foi verificado o ângulo de parede máximo atingido por cada processo de estampagem incremental. Adicionalmente, ensaios de tração, análise de deformações e de rugosidade da chapa de latão foram realizados. Todos os seus resultados estão detalhados na investigação. Para os parâmetros adotados nestes experimentos, o ângulo de parede obtido por SPIF foi maior do que pelo estudo proposto por MSPIF. / The present study investigates the performance of the brass plate C-268 with 0.50 mm thickness, when exposed to Incremental Sheet Metal Forming (ISMF). Specifically for research, it was used the modalities Single Point Incremental Forming (SPIF) and Multi Pass Single Point Incremental Forming (MSPIF). The experiments were based on a truncated pyramid geometry with square base 100 mm side and 45 mm depth. For forming strategies has been assigned, the helical forming. As the main outcome, it was found the maximum wall angle achieved by each process of incremental printing. In addition, tensile tests, analysis of deformation and roughness of the brass sheet were performed. All results are detailed in the investigation. For the parameters used in these experiments, the wall angle obtained by SPIF is greater than the study proposed by MSPIF.

A estampagem incremental é um processo de deformação incremental de chapa que pode ser classificado em três modos distintos: estampagem incremental sem matriz, estampagem incremental com matriz parcial e estampagem com matriz total. A deformação ocorre devido ao contato entre a ferramenta e a chapa, localmente e progressivamente, ao longo de uma trajetória pré-definida. A chapa permanece presa a suportes que fixam as suas extremidades de maneira a impedir os deslocamentos provocados pela passagem da ferramenta. A primeira parte deste trabalho compreende estudos em elementos finitos, usando o software LS-Dyna, sobre a trajetória das deformações na estampagem incremental para a fabricação de flanges em chapas previamente furadas de liga de alumínio AA1050. Foram realizados testes de contato e de linha que permitiram definir parâmetros da simulação. Os resultados para as deformações foram confrontados com os resultados obtidos experimentalmente por outros autores e permitiram verificar o comportamento das deformações nos flanges. As deformações crescem montonicamente até os valores máximos. Este resultado confirma a teoria de que na estampagem incremental de chapas a fratura ocorre sem o prévio aparecimento da estricção. A segunda parte deste trabalho trata do desenvolvimento de um suporte modular aplicável a estampagem incremental, tanto na sua variante sem matriz quanto com matriz, com o intuito de aumentar a flexibilidade do processo com relação à geometria da peça a ser deformada. Foi empregada a técnica de análise de valor objetivando alcançar a melhor funcionalidade do sistema. Como resultado foi obtido um suporte modular que atende os requisitos de rigidez, flexibilidade, modularidade, agilidade na troca da chapa a ser deformada e simplicidade construtiva. / The sheet incremental forming can be classified into three basic configurations, depending on the number of contact points between the sheet, tool and die (when present). Single incremental forming (absence of specific dies) and two point incremental forming (presence of a partial or full die) can be distinguished. The process makes use of a simple, low-cost, hemispherical tipped tool to precisely and progressively shape a blank into a metal sheet along a predefined tool path. The sheet is fixed onto the rig to prevent lateral displacements caused by tool movement. The first part of this work includes studies about finite elements, using the LS-Dyna software, applied to deformation path in hole-flanging produced by incremental sheet forming. The investigation was carried out using aluminum alloy AA1050. Contact and line numerical results support simulation parameters choices. The results from the strains were compared with empirical ones obtained by other authors. The results showed the deformation mechanics behavior of the hole-flanging. The strain paths of hole-flanging produced by incremental sheet forming grew linearly and monotonically from the origin to the maximum achievable strains. This result confirms the absence of local necking along plane strain directions. The second part of this work deals with the development of a modular rig that can be applied to dieless, partial or total die single point incremental forming in order to increase the flexibility of the process concerning the geometry of the part to be deformed. The result was a modular rig with constructive simplicity and requirements of stiffness, flexibility and modularity when exchanging sheets.

No description available.