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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Optimalizace výroby součásti na hlubokotažném lisu / Optimization of components production on draw press

Rérych, Pavel January 2019 (has links)
The diploma thesis present technology production of draining outlet. This is a rectangular deep drawn part, where basic shape is formed in two towing operations now. The used material is an austenitic stainless steel 17 240 with thickness 1 mm. According to the entry documentation the production technology was not change – current technology (it means drawing without thinning the wall) is most suitable. Based on technological and control calculations two-operations production was determined, which will take place in the united conventional instrument. The hydraulic press with marking Dieffenbacher PO250, which has a magnetic tool clamping, per stroke will perform here both operations. The payback was calculated for yearlong production 50 000 pieces after 0,8 years. The proposed production will make the current production more efficient including economic benefits.
12

Optimalizace procesu výroby vpusti / Optimization of production process of drain

Staněk, Vojtěch January 2012 (has links)
The project looks for a solution to optimalization of rotational deep drawn part with flange production. It deals with sewerage drain, which is produced by conventional tool to two deep drawing operations. The used material is austenitic Cr-Ni stainless steel 1.4301. Suitability of this material for deep drawing operations was considered by means of the tensile test and the Erichsen test. On the bases of these results, serializability of production and theoretic relationships for determination of number of deep drawing operations, it was decided upon one operation serial production, by conventional tool without attenuation thickness of sheet. Production will take place on hydraulic press Dieffenbacher PO250 with magnetic tool fastening. The deep drawing tool was designed and constructed. For series of 2 000 units per year the rate of return was calculated after 4,7 years, while using the punch from the current second deep drawing operation it was calculated after 3,4 years.
13

Tažení plechu a jeho verifikace počítačovou simulací / Sheet metal drawing and its verification by computer simulation

Něnička, Filip January 2012 (has links)
This thesis engages on the differences between the numerical simulations of sheet metal drawing process performed using AutoForm software from AutoForm Engineering, Swiss company and actual results measured using non-contact measurement system Argus from German GOM company. This work used DC06 material (whose mechanical properties were determined at Technical University of Liberec) for comparison. The calculated results of simulations were compared to measured results of actual plate thickness.
14

Entwicklung und Umsetzung eines Moduls zur Inline-Faltenauswertung an Kartonziehteilen / Development and Implementation of a Module for inline-examination of wrinkle-distributions on deep-drawn paperboard containers

Meyer, Martin 16 February 2016 (has links) (PDF)
Die vorliegende Arbeit hat die Entwicklung und Validierung eines Inline-Faltenauswertungsmoduls zur Auswertung der Faltenverteilung an gezogenen Kartonformteilen im Prozess zum Ziel. Ein entsprechend konstruierter Versuchsaufbau ermöglicht die dafür notwendigen Bilddaten innerhalb des Ziehprozesses zu akquirieren und annähernd in Echtzeit auszuwerten. Durch den Ausgleich der graduellen Beleuchtung kann unter Anwendung eines zweidimensionalen Frequenzfilters eine Kontrastoptimierung zwischen Falten und Hintergrund erreicht werden, die die Auswertung der Daten begünstigt. Mittels Kreuzkorrelation mit einem Faltenmodell kann so die Position von Falten in Bildausschnitten lokalisiert werden. Dieser neuartige Ansatz ermittelt Falten nicht nur punktuell, sondern bezieht auch die Umgebung eines Pixels in die Analyse ein. Dadurch wird eine differenzierte Klassifizierung erreicht, die robust gegenüber Bildfehlern und Rauschen ist. Eine Korrekturfunktion berücksichtigt die durch die Abbildung der runden Zarge auf die Fokusebene resultierenden Positionsabweichungen und macht die Falten einer photogrammetrischen Messung zugänglich. So lassen sich mittlere Faltenabstände und deren Standardabweichungen ermitteln, die einem Vergleich mit Referenzmessmethoden standhalten. Mit Hilfe statistischer Tests kann gezeigt werden, dass vor allem aus hohen Faltenhalterkräften, und demzufolge feinverteilten Falten, größere Abweichungen zwischen dem Inline-Faltenauswertungsmodul und der Referenzmessmethode resultieren. Eine Fehlerdiskussion legt verschiedene Gründe für dieses Verhalten dar. Weiterführende Untersuchungen weisen die prinzipielle Eignung des Verfahrens für abweichende Geometrien und Materialien nach, zeigen jedoch auch Grenzen des eingesetzten Systems auf. Basierend auf den gewonnenen Erkenntnissen werden Verbesserungsansätze vorgeschlagen, die die Limitierungen der entwickelten Methode reduzieren können. / The present thesis includes the development and validation of a module for inline-examination of wrinkle-distribution on deep-drawn paperboard containers within the deep drawing process. A suitably constructed test-device allows to acquire the necessary images within the process and their approximately real-time evaluation. The usage of a two-dimensional frequency-filter accomplishes a contrast optimization between wrinkles and background by the compensation of a gradual illumination, which supports the evaluation of the wrinkles. Through the cross-correlation with a wrinkle-model, the position of wrinkles in image segments can be determined. This novel approach not only determines the wrinkles in a punctual way, but also it includes the environment of pixels. In this way a differentiating classification is possible, which is sturdy against image errors and noise. A correcting function considers the position errors caused by the mapping of the round frame of the deep-drawn paperboard container to the focal plane and makes the wrinkles available for a photogrammetric measurement. In this way averaged wrinkle-distances and their standard deviation can be determined that withstands the comparison with certain reference measuring methods. By statistical tests can be shown, that especially high blankholder forces and therefor small wrinkles result in higher differences between the inline examination-module and the reference measuring method. An error discussion explains various reasons for this behavior. Further tests prove the general suitability of the method for different geometries and materials, but also show limits of the applied system. Based on the gained knowledge, approaches for optimization are discussed that may improve the developed method.
15

Development of a test method for measuring galling resistance

W. Lindvall, Fredrik January 2007 (has links)
<p>Abstract</p><p>Today sheet metal forming is used to make a variety of mass production because it has a high production rate. One of the biggest concerns in sheet metal forming is wear of the tool in form of galling. Galling in sheet metal forming is characterised by an increased tool surface roughness, unstable friction in the forming process and undesirable scratches on the final products.</p><p>Several ways of ranking materials resistance to galling exist today but only ASM G98 is standardised. Nevertheless, some different methods developed for ranking tool materials’ tendency to galling have also been developed.</p><p>The aim of this thesis is to develop and improve the Uddeholm Tooling Tribo Test rig located at Uddeholm Tooling AB. The rig, which is a variation of cylinder-on-cylinder test equipment, was improved with a new tool holder, a utilization of the real sheet material counter face and a new data acquisition system and software. The galling was detected using scratches on the sheet, metallographic analysis of the material adhered on the tool specimen, monitoring of coefficient of friction and the standard deviation of the coefficient of friction.</p><p>The obtained results show difficulties with ranking of tool materials in terms of galling resistance under non-lubricated conditions. The tool steels tested were SVERKER21 and UNIMAX. AISI304-10, DC04 and DOCOL1000DP sheets were used. Additionally a low friction coating of BalinitC on SVERKER21 was also included. All specimens of the tool steels showed signs of galling on every run, only the low friction coating showed a transition in behaviour of friction coefficient corresponding to galling initiation. The standard deviation of the coefficient of friction increased at low loads. A decrease of the test loads led to stability loss of the system detected by an increase in the standard deviation of the coefficient of friction. This might happen because the Kistler platform is originally designed for larger loads. Although, the test rig does not work properly in its present state, the concept looks promising.</p>
16

Análise do coeficiente de atrito determinado pelo método de dobramento sob tensão aplicado ao processo de estampagem profunda

Schumann, Adriano Leonardo January 2018 (has links)
O presente trabalho tem por finalidade apresentar e discutir os resultados encontrados para o coeficiente de atrito de três tipos de diferentes chapas utilizadas em processos de estampagem na indústria automotiva. O método adotado para determinação do coeficiente de atrito foi o dobramento sob tensão, método este que tem por finalidade simular as condições de uma operação de embutimento. Os resultados apresentados demonstram que diferentes chapas em aço NBR 5915 EM e EMS ME 1508 EM, com ou sem proteção galvânica, apresentam diferentes condições tribológicas determinadas através do ensaio. Coeficientes de atrito que variam desde 0,103 até 0,151 foram determinados, considerando condições de lubrificação e de ferramenta constantes. A influência do coeficiente de atrito no processo é exemplificada através do cálculo da força máxima de estampagem, sendo que para as mesmas condições de propriedades mecânicas a variação do coeficiente de atrito provocou um aumento de 7,6% na força máxima. Através do cálculo determinou-se também a influência do coeficiente de atrito nas forças de atrito do processo. Para as condições apresentadas, a influência do coeficiente de atrito no prensa chapas na força máxima de estampagem é 20x menor em relação à influência do coeficiente de atrito no raio da matriz. / This research aims to show and discuss the friction coefficient of three different kinds of sheet metal used in sheet metal forming processes of automotive industry. The methodology for the determination of the coefficient of friction was the bending under tension, that purpose to simulate the deep drawing conditions. The results show different kinds of sheets metals, as NBR 5915 EM and EMS ME 1508 EM, with or not galvanized protection, show different tribological conditions by the tests. Friction coefficients from 0,103 to 0,151 were founded, considering invariable lubrication and tool conditions. The influence of friction coefficient in the stamping process is exemplified by the maximum stamping strength. For these tests conditions, the coefficient of friction caused an increase of 7.6% in the maximum stamping strength. The influence of the friction coefficient on the friction strengths of the process was determined. For these conditions, the influence of the friction coefficient in the friction strength of the blank holder is 20x smaller than in the friction strength of die's radius.
17

Caracterização e comparação dos procedimentos de obtenção da curva limite de conformação e das características de estampagem dos aços inoxidáveis DIN 1.4509 e AISI 321. / Characterization and comparison of the procedures for obtaining the Forming Limit Diagram and the deep drawing characteristics of DIN 1.4509 and AISI 321 stainless steels.

Pisano, Caio de Paula Camargo 29 June 2017 (has links)
Com a grande demanda do mercado brasileiro, e mundial, por desenvolvimento de novas tecnologias, redução de custos e de complexidade, os processos industriais buscam cada vez mais alternativas inovadoras. Para que essa evolução seja possível, é fundamental que todos os componentes da cadeia industrial também se desenvolvam, tornando assim as matérias primas, como aços, polímeros, alumínio, e outros metais que estão na base da cadeia, um grande foco de estudos. A indústria siderúrgica, em específico, vem buscando este desenvolvimento nos últimos anos, trabalhando principalmente no desempenho que os materiais terão nos processos industriais, tais como estampagem, soldagem e muitos outros. O processo de estampagem requer o desenvolvimento destes materiais, já que este solicita matérias primas com um bom desempenho mecânico, capaz de absorver possíveis variações e dificuldades que existem em uma linha de produção industrial. Para que este objetivo seja atingido, deve-se dedicar tempo e recursos para encontrar a combinação ideal entre pesquisa e processo produtivo e, assim, otimizar as características mecânicas e químicas dos materiais para o desenvolvimento da cadeia industrial. No contexto da estampagem há um bom indicativo para prever qual será o desempenho de um material: a Curva Limite de Conformação (CLC). Neste presente trabalho os conceitos da CLC serão discutidos, e aplicados a dois aços inoxidáveis distintos, um da família ferrítica (DIN 1.4509) e outro da família austenítica (AISI 321). Além disso, também serão abordadas as principais características metalúrgicas e mecânicas, correlacionadas à estampagem, destes materiais e as principais formas de utilizar estas informações na prática industrial com o objetivo de aperfeiçoar o desempenho do material nos processos e principalmente, quando possível, promover a migração de uma liga austenítica, por uma liga ferrítica, com o objetivo de redução e estabilidade nos custos. / With the increase of the market demand, both in Brazilian, and in the world, for the development of new technologies, cost and complexity reduction, the industrial processes have been investigating for innovative solutions. In order to this evolution to take place all industrial chain players would have to develop. Therefore all raw materials, such as steels, polymers, aluminum and other metals are in evidence to become the focus of investigation. The steel industry, in particular, has been searching for this evolution over the last years, working in their processes with the goal to increase the performance of the grades on the industrial processes, such as deep drawing, welding, and many others. The deep drawing process is a great motivator to the development of the steels, since it requires a high mechanical performance from the material, to absorb possible variations and difficulties which may occur in an industrial production line. In order to achieve this goal, time and resources must be spent to find the perfect combination between research centers and production processes, optimizing the chemical and mechanical characteristics of the steels, so the development of the whole chain can also advance. Within the deep drawing field of study, a good indicative to predict the material\'s performance is the Forming Limit Diagram (FLD) and in this work the concepts of these FLD\'s will be discussed and applied to two stainless steel grades: a ferritic stainless steel (DIN 1.4509) and an austenitc stainless steel (AISI 321). In addition, the main metallurgical and mechanical properties of these materials, related to the deep drawing, will be approached along with the best ways to apply this kind of information to the industrial practices, in order to increase the material performance and, whenever possible change the austenitic stainless steel to the ferritic stainless steel, in order to reduce and keep the costs stable.
18

Desenvolvimento de um programa paramétrico para simulação do processo de estampagem utilizando elementos finitos /

Guidi, Erick Siqueira. January 2009 (has links)
Orientador: Fernando de Azevedo Silva / Banca: Angelo Caporalli Filho / Banca: Ricardo Risso Chaves / Resumo: Dentre os processos de conformação mecânica de metais por deformação plástica, a estampagem possui grande importância por possibilitar a obtenção de produtos de diversos formatos, semi-acabados ou acabados e com boas propriedades mecânicas. A simulação computacional utilizando o método dos elementos finitos apresentou um grande desenvolvimento na última década, hoje é uma importante ferramenta de análise de projetos. Neste trabalho é apresentada a elaboração de um arquivo paramétrico, em linguagem APDL, de simulação do processo de estampagem de copos cilíndricos para o programa comercial ANSYS® 7.0. Este arquivo é construído de maneira automática por um programa criado no software de programação DELPHI 7.0. O paramétrico irá auxiliar o projetista na análise das variáveis do processo de estampagem e no desenvolvimento de ferramental, permitindo realizar um estudo dessas variáveis de maneira isolada ou com vários fatores simultâneos. Para a validação do arquivo paramétrico foram realizados ensaios que foram confrontados com os resultados obtidos nas simulações. / Abstract: Among the processes of forming metals by plastic deformation, the stamping possesses great importance for facilitating the obtaining the products of several formats, near net-shape or net-shape and with good mechanical properties. The computacional simulation using the finite elements method presented a great development in the last decade, today it is an important tool of analysis the projects. In this work the elaboration of a parametric file, in language APDL, of simulation of the stamping process of cylindrical cups for the commercial program ANSYS® 7.0. This file is built in an automatic way by a program making in the programming software DELPHI 7.0. The parametric will help the designer in the analysis of the stamping process variables and development of tools, allowing accomplishing a study of these variables alone or with several factors simultaneously. For validation of the file parametric was accomplished experimentals that were confronted with the results obtained in the simulations. / Mestre
19

Desenvolvimento do processo de estampagem para miniaturização de motores / Micro deep drawing applied in the fabrication of micromotors

Boff, Uilian January 2012 (has links)
O processo de microestampagem permite a fabricação de peças ou microcomponentes, podendo ser aplicado a diversas áreas da engenharia. Logo, este trabalho tem por objetivo desenvolver um micromotor de passo e avaliar os efeitos da miniaturização de seus componentes. A simulação computacional foi utilizada neste trabalho de forma a avaliar os defeitos surgidos com a miniaturização, através do software de elementos finitos DYNAFORM com “solver” LS-DYNA. O material empregado na carcaça foi o aço de baixo carbono ABNT 1010 e o aço inoxidável ABNT 304, e para o núcleo magnético do micromotor, composto pelo rotor e estator, utilizou-se o aço elétrico ABNT 35F 420M. A simulação computacional, além de identificar os problemas oriundos da miniaturização dos componentes, também foi utilizada para otimizar as ferramentas de microestampagem, demonstrando desta forma ser uma grande aliada para o desenvolvimento do processo. O processo de corte convencional em matriz não foi aplicado no corte do rotor e do estator, pois produziu defeitos como empenamento e rebarbas. Ao invés disso, empregou-se o processo de corte por eletroerosão a fio, que produziu peças planas e superfícies lisas. / The process of micro deep drawing is a micro-technology which allows the fabrication of microcomponents and can be applied to various fields of engineering. This study aims to develop the components of a micromotor step using this technology and to evaluate the effects of the microfabrication of the motor frame, rotor and stator. A computer simulation was carried out in order to evaluate miniaturization of the components trough the finite element software DYNAFORM with “Solver” LS-DYNA. The material used in the motor housing was low carbon steel ABNT 1010 and stainless steel ABNT 304. However, in magnetic core, comprising the rotor and stator, the electric steel ABNT 35F 420M was employed. Micro deep drawing tools were developed based on the results obtained through simulation is a great ally to create microcomponents. The cutting process in the matrix was not employed to cut de rotor and the stator, because it produced defects such as warping and butts along the surface. Instead, wire cutting spark erosion was used and resulted in hat part and surfaces.
20

Vergleich von Strategien zur Simulation der Kompression in Blattebene bei der 3D Umformung von Karton

Wallmeier, Malte 25 February 2013 (has links) (PDF)
Die vorliegende Arbeit hat die Entwicklung eines Konzepts für das Materialmodell zur Simulation des Ziehprozesses mit Karton zum Ziel. Der Ziehprozess stellt bei seiner Simulation hohe Anforderungen an das verwendete Materialmodell. Mehrachsige Spannungszustände und die Einflüsse von Temperatur und Feuchtigkeit müssen berücksichtigt werden. Dazu werden Materialverhalten, Materialmodelle und ihre mathematisch-physikalischen Grundlagen, Spannungssituation und Anforderungen des Ziehprozesses an ein Materialmodell analysiert. Es wird ein Konzept dargelegt, in dem die Simulation des Ziehprozesses in drei Schritte unterteilt wird. Im ersten Teil werden Materialfeuchte und Temperatur mit einem zweidimensionalen Netzwerkmodell bestimmt. Im zweiten Schritt werden Materialparameter mit Hilfe eines dreidimensionalen Netzwerkmodells in Abhängigkeit von zuvor ermittelten Feuchte- und Temperaturwerten und mechanischer Belastung gewonnen. Diese Parameter werden im dritten Teil zur Simulation des Ziehprozesses mit einem makromechanischen Materialmodell genutzt. / A concept for the development of a paperboard material model for the simulation of deepdrawing processes is presented in this thesis. Concerning its simulation, the deep drawing process of paperboard is demanding. Complex states of tension, humidity and changes of temperature during the process have to be considered. Thus properties of paperboard, material-models, their mathematical-physical background and tensions during the deep-drawing process are analyzed. A concept for the material-model, dividing the simulation in three steps, is proposed. In the first step, temperature and humidity are determined, using a two-dimensional lattice model. During the second step material parameters, depending on the state of tension are evaluated with a three-dimensional lattice model. The third step contains the simulation of the deep-drawing process with a three-dimensional continuum model.

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