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Suvirinimas elektros lanku yra labai paplitęs visose pramonės šakose. Daugeliu atveju iškyla problemų skaičiuojant ir projektuojant įrenginius, kurie virina elektros lanku. Siekiant pašalinti šiuos sunkumus vis labiau nagrinėjami suvirinimo elektros lanku pereinamieji procesai. Virinant šiuo būdu įvykus trumpajam jungimui vyksta pereinamieji procesai, kurių metu gaunamas gamybinis brokas. Todėl norint pagerinti suvirinimo siūlės kokybę, siekiama, kad kuo greičiau atsistatytų visos sistemos darbinės charakteristikos. Didžiausią reikšmę suvirinant turi elektros lanko įtampa. Šiame darbe nagrinėjami suvirinimo lanko maitinimo šaltiniai, įtampos reguliavimo būdai ir suvirinimo lygintuvai. Tiriamojoje dalyje sudaryta funkcinė schema ir automatinio reguliavimo sistemos struktūrinė schema. Naudojantis programinės įrangos Matlab paketu apskaičiuoti pareinamieji procesai. / Electric arc welding is very popular in all branch of industry. There is a lot of problem to calculate and design equipments with boiling electric arc. On purpose eliminate this problems look into transition process for electric arc welder. Bolding in this way processing short conection we have transition process and get manufacturing spoilage. On purpose to have better welding seam we have to have more faster running system characteristic. The most biggest importance of bolding have voltage of welding seam. In this project we will research welding seam feeding sourse, voltage controlling way and bolding leveler. In the inquiring part we will build functional scheme and system flowchart of automatic control. Using Matlab program we will produse transitive process.

A multivariable control technique is proposed for a type of nonlinear system with parameter intervals. The control is based upon the feedback linearization scheme called Generic Model Control, and alters the control calculation by utilizing parameter intervals, employing an adaptive step, averaging control predictions, and applying an interval problem solution. The proposed approach is applied in controlling both a linear and a nonlinear arc welding system as well in other simulations of scalar and multivariable systems.

In gas metal arc welding (GMAW), metal transfer plays a crucial role in determining the quality of the resultant weld. In the present dissertation, a numerical model with advanced computational fluid dynamics (CFD) techniques has been developed first in order to provide better numerical results. It includes a two-step projection method for solving the incompressible fluid flow; a volume of fluid (VOF) method for capturing free surface; and a continuum surface force (CSF) model for calculating surface tension. The Gauss-type current density distribution is assumed as the boundary condition for the calculation of the electromagnetic force. The droplet profiles, electric potential and velocity distributions within the droplet are calculated and presented for different metal transfer modes. The analysis is conducted to find the most dominant effects influencing the metal transfer behavior. Comparisons between calculated results and experimental results for metal transfer under constant current are presented and show good agreement. Then, our numerical model is used to study a proposed modified pulsed current gas metal arc welding. This novel modified pulsed current GMAW is introduced to improve the robustness of the welding process in achieving a specific type of desirable and repeatable metal transfer mode, i.e., one drop per pulse (ODPP) mode. This new technology uses a peak current lower than the transition current to prevent accidental detachment and takes advantage of the downward momentum of the droplet oscillation to enhance the detachment. The calculations are conducted to demonstrate the effectiveness of the proposed method in achieving the desired metal transfer process in comparison with conventional pulsed current GMAW. Also, the critical conditions for effective utilization of this proposed method are identified by the numerical simulation. The welding operational parameters and their ranges are also calculated and the calculated results further demonstrate the robustness of this new GMAW technique in achieving high quality welding.

The Quasi-Keyhole plasma arc welding (PAW) process is a relatively simple concept, which provides a basis for controlling the weld quality of a subject work piece by cycling the arc current between a static base and variable peak level. Since the weld quality is directly related to the degree of penetration and amount of heat that is generated and maintained in the system, the Non-Linear Interval Control Algorithm provides a methodology for maintaining these parameters within acceptable limits by controlling the arc current based upon measured peak current times. The Texas Instruments TMS320VC5416 DSK working in conjunction with Signalwares AED-109 Data Converter provides a hardware solution to implement this control algorithm. This study outlines this configuration process and demonstrates its validity.

The need and desire to create robust and accurate joining of materials has been one of up most importance throughout the course of history. Many forms have often been employed, but none exhibit the strength or durability as the weld. This study endeavors to explore some of the aspects of welding, more specifically relating to the Double Sided Arc Welding process and how best to model the dynamic non-linear response of such a system. Concepts of the Volterra series, NARMAX approximation and neural networks are explored. Fundamental methods of the neural network, including radial basis functions, and Back-propagation are investigated.

<p>Det finns flera fördelar med robotiserad bågsvetsning jämfört med manuell bågsvetsning. När det gäller produktivitet och repeterbarhet är robot överlägsen människa, vilket gör att produkterna håller jämnare kvalitet. I slutet av 80-talet började offline-programmering att tillämpas. Att programmera en robot offline innebär att utföra programmeringen med dator utan direkt tillgång till roboten. Genom simulering visualiseras ett robotprogram i en grafisk modell av den fysiska robotcellen utan att den fysiska roboten behöver tas ur produktion. För att systemet för offline-programmering (OLP) ska vara effektivt, måste dess modellers kinematik överensstämma med dess fysiska motsvarigheter. En virtuell modell av en cell skiljer sig dock alltid något från verkligheten. Därför krävs kalibrering När simuleringsprogrammet är färdigt och kalibreringen är utförd, ska programmet översättas till ett för roboten specifikt programspråk. Detta görs genom en så kallad translator.</p><p>Denna rapport har skrivits på uppdrag av Delfoi. Delfoi har i flera år använt sig av DELMIA IGRIP för offline-programmering av bågsvetsningsrobotar. DELMIA har nu gett ut en ny generation program i den gemensamma plattformen V5. Plattformen innehåller bland annat DELMIA V5 Robotics och CATIA V5. Området för bågsvetsning har varit relativt outforskat. Därför vill företaget undersöka hur långt V5 Robotics har utvecklats inom detta område. Syftet är att undersöka om utvecklingen av V5 Robotics kommit tillräckligt långt för att kunna säljas till kund för offline-programmering av bågsvetsning.</p><p>Arbetet påbörjades genom att kartlägga den arbetsmetodik som Delfoi använder sig av vid bågsvetsning i IGRIP. Detta har skett i programvaran UltraArc, som innehåller IGRIP’s applikation för bågsvetsning. Dessutom gjordes en kartläggning av användandet av AMP, Arc weld Macro Programming, vid offline-programmering av bågsvetsning. Nästa del var att ta fram en metodik för bågsvetsning i V5 Robotics. De båda programmen och dess metodik har sedan jämförts, för att ta reda på om V5 Robotics är tillräckligt utvecklat för att migrera från IGRIP till V5 Robotics. Demonstrationer av arbetssättet i V5 Robotics har genomförts på Delfoi samt hos en av Delfois kunder, BT Industries i Mjölby.</p><p>Författarnas slutsats är att V5 Robotics är redo att användas för OLP av bågsvetsning. För de företag som använder sig av CATIA V5 finns det stora fördelar med att starta migrationen från IGRIP till V5 Robotics. Metodiken mellan de båda mjukvarorna har stora likheter, men vissa delar har utvecklats till det bättre i V5 Robotics. Dock kan den nya programvaran behöva testas i verkliga projekt för att säkerställa att hela programmeringsprocessen fungerar tillfredsställande innan bytet genomförs.</p> / <p>There are several advantages in robotic arc welding, compared to manual arc welding. When it comes to productivity and repeatability, robot is superior to man, which generates more even quality in products. In the end of the 1980’s, offline programming was put into practice. To program a robot offline means to perform the programming on a computer with no direct access to the robot. Through simulation, the robot program is visualized as a graphic model of the actual workcell, without having to take the actual robot out of production. For the offline programming system (OLP) to be efficient, the kinematics of the models need to correspond to its physical counterpart. A virtual model is always slightly different from the reality. That is why calibration is necessary. When the simulation program is complete and the calibration is done, the program needs to be translated to the language of the target robot. This is done through a post processor.</p><p>This thesis was written as an assignment from the company Delfoi. Delfoi has been using DELMIA IGRIP for offline programming of robotic arc welding for several years. DELMIA now has released a new generation of programs in the common platform V5. The platform includes for example DELMIA V5 Robotics and CATIA V5. The area of arc welding has been relatively unexplored. That is why the company wants to investigate how far V5 Robotics has developed in this area. The purpose is to investigate if the development of V5 Robotics has come far enough for V5 Robotics to be taken to customers for OLP of arc welding.</p><p>The work was begun by surveying the methodology used by Delfoi in arc welding in IGRIP. This has been done in the software UltraArc, which consists of the arc welding application from IGRIP. There was also a surveillance of the application of AMP, Arc weld Macro Programming, in offline programming of arc welding. The next step was to evolve a methodology for arc welding in V5 Robotics. The two softwares and their methodologies were then compared to find out whether or not V5 is enough developed for migration from IGRIP to V5 Robotics. Demonstrations of the method of working in V5 Robotics were held on Delfoi and on BT Industries in Mjölby, which is one of Deloi’s clients.</p><p>The conclusion of the writers is that V5 Robotics is ready to be used in OLP of arc welding. For companies using CATIA V5, there are great advantages in migrating from IGRIP to V5 Robotics. The methodoldgies of the softwares show great similarities, but some parts have been developed to the better in V5 Robotics. Though, the new software needs to be tested in real projects to assure that the entire process of programming functions satisfying before the change is completed.</p>

Made available in DSpace on 2014-06-11T19:27:13Z (GMT). No. of bitstreams: 0 Previous issue date: 2006-10-26Bitstream added on 2014-06-13T18:55:40Z : No. of bitstreams: 1 araujo_mrv_me_ilha.pdf: 2852795 bytes, checksum: d4a04e4f21fe65d5c85b4c75afe42115 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O processo de soldagem por Arco Submerso é um dos processos de soldagem mais importantes na fabricação de modernas estruturas de engenharia, utilizado na fabricação metálica como tubos, navios, perfis, vasos de pressão e trocadores de calor, diferencia-se dos demais processos de soldagem pela utilização de um fluxo granular composto basicamente de componentes minerais como óxidos e silicatos. Este fluxo é alimentado à região de solda proporcionando uma solda sem respingos, luminosidade e radiação, além de proteger a região de solda da oxidação atmosférica. As propriedades mecânicas dependem da microestrutura do metal de solda, neste sentido, estudos realizados demonstram que a microestrutura ferrita acicular possui uma ótima combinação entre resistência mecânica e tenacidade. Inclusões não metálicas presentes no metal de solda podem promover a formação da ferrita acicular durante a transformação de fase, no entanto há nucleação de outras microestruturas. A microestrutura ferrita acicular (AF) depende da composição e tamanho das inclusões não metálicas presentes no metal de solda. Estas inclusões são geralmente óxidos, silicatos que são formados durante o processo de soldagem. Algumas substâncias como a zircônia e zirconita são potenciais nucleadores da ferrita acicular, neste sentido adicionou-se no metal de base a zircônia, zirconita e alumina para análise de uma eventual participação destes aditivos na formação da microestrututura do metal de solda. .Os ensaios de soldagem foram realizados com controle e monitoramento dos parâmetros elétricos, visto que estes são fatores importantes na formação da geometria do cordão de solda. Os materiais utilizados como metal de base... / Submerged-Arc Welding (SAW) is one of the most important welding processes applied in the fabrication of modern engineering structures. During the deposition of molten steel, which is protected against oxidation by agglomerated flux layer, the microstructure of the weldment undergoes considerable changes because of the heating and cooling cycles directly related to the welding process were employed. Mechanical properties of welded joint can be improved by a well design welding microstructure. Some studies have shown that acicular ferrite provides an optimum combination of strength and toughness in steel weld metal. The flux formulations are prepared using mineral compounds, such as oxides and silicates, and it is possible to increase the content of acicular ferrite by higher quantity of intragranular nucleation sites. So, dispersed non-metallic inclusions can promote the formation of acicular ferrite during phase transformation, at the expense of other undesirable weld phases such as allotriomorphic and Widmanstätten ferrite. In experimental procedure ASTM A36 steel grade was used as a metal base, together AWS E70-S6 solid wire and a commercial active flux commonly applied for SAW processing. Bead on plate welding was performed in flat position and nominal heat input changed from 1.0 to 3.3 kJ/mm. Transverse sections of weld deposit were prepared according standard grinding (up to 1200-grit SiC paper) and polishing (1.0 æm alumina) methods, followed by moderate etching in 2% nital for optical microscopy (OM). So, it was possible to determine some important weld bead geometry parameters such as penetration, reinforcement and bead width. Using quantitative metallography techniques allowed that some microstructure features were determined too... (Complete abstract click electronic access below)

Made available in DSpace on 2014-10-09T12:44:30Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T13:57:21Z (GMT). No. of bitstreams: 1 06907.pdf: 7394695 bytes, checksum: bde9c680792583e55f4754af5867fe98 (MD5) / Dissertacao (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP

O aporte térmico, ou imposição de calor, é uma das características com grande importância nos processos de soldagem, pois ela está diretamente relacionada com as propriedades mecânicas e as transformações metalúrgicas da junta soldada. Neste sentido, este trabalho propõe o projeto, a construção e a validação de um calorímetro com uma vazão contínua de água para avaliação do aporte térmico e da eficiência térmica em processos de soldagem a arco elétrico que seja de baixo custo, adaptável aos diferentes processos de soldagem, de simples operação e fácil movimentação. Foram realizados experimentos com três processos, sendo eles: soldagem a arco com gás de proteção e eletrodo consumível (GMAW – Gas Metal Arc Welding), soldagem a arco com eletrodo não consumível e gás de proteção (GTAW – Gas Tungsten Arc Welding) e soldagem ao arco submerso (SAW – Submerged Arc Welding). As atividades realizadas visam identificar o efeito sobre a eficiência térmica devido à variação de alguns dos parâmetros de soldagem bem como identificar características intrínsecas do calorímetro construído. Para o processo de soldagem GMAW verificou-se um rendimento médio do arco de 72,82%, com uma eficiência média de 71,10% especificamente para o processo GMAW com transferência metálica goticular e de 76,26% para transferência metálica por curto-circuito. O processo de soldagem GTAW apresentou uma eficiência térmica média de 68,44% e para o processo SAW foi observado um rendimento do arco de 91,05%. Os resultados obtidos se mostraram coerentes quando comparados aos valores reportados anteriormente por outros autores e também apresentaram uma boa repetitividade, sendo de 4,5% a maior diferença observada entre cordões de solda de um mesmo experimento. / Heat input is an important welding process characteristic since it is directly related to the mechanical properties and metallurgical transformations of the welded joint. This paper aims to present the project, construction and validation of a calorimeter with continuous water flow to evaluate the heat input and the thermal efficiency of arc welding processes. The proposed calorimeter shall have a low cost, versatile, easy to handle and to operate. Experiments were carried out with gas metal arc welding (GMAW), gas tungsten arc welding (GTAW) and submerged arc welding (SAW). These activities aimed to identify the effect that changes of certain welding parameters perform on the thermal efficiency and to identify intrinsic characteristics of the proposed calorimeter. For GMAW processes it was obtained a global thermal efficiency of 72.82%. For this process, the results were different according to the metal transfer: 71.10% for GMAW with spray transfer and 76.26% for GMAW with short circuit transfer. The average thermal efficiency obtained for the GTAW was of 68.44% and for the SAW process was of 91.05%. The experiments results showed to be consistent when compared to previously reported values by other authors and also showed good repeatability, where the large difference observed between weldments of the same experiment was of 4.5%.