• Proceedings of the Korea Society for Simulation Conference
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• 2005.11a
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• pp.113-121
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• 2005

Virtual Manufacturing is a powerful methodology for developing a new product, new equipment and new production system. It enables us to check the errors in design before production. This paper deals with a case study of virtual manufacturing in an excavator factory. Boom and rotating table of upper body are selected for application. 3D models of parts and fixtures are developed with CATIA and 3D simulation models are developed with IGRIP. These models are used for the design of fixture to verify the motion of the equipment. As a result, the manual welding systems are replaced by automatic systems and many design errors are corrected in the design phase, which enables us to reduce the developing cost and time.

• Proceedings of the KSME Conference
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• 2003.11a
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• pp.1757-1762
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• 2003

For coping with various ship types easily, welding automation using CAD/CAM is demanded and and developed. In this paper we propose a dedicated CAM system which generates MACRO files to control robot manipulators. The paper contains CAD interface, virtual simulation, macro generation and job schedulling. At first, it defines and extracts weldline from CAD data, and generates proper MACRO programs. And it obtains optimum job schedules. This system removes the manual work, and consequently reduces the overall lead time. And it reduces costs and time for developing robot welding programs. This can be expanded to virtual factory simulation technology. Moreover, it is possible to apply this system for automation of Cutting and Painting

• Laser Solutions
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• v.13 no.2
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• pp.17-23
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• 2010

It is very important to track a complicate weld seam for the welding automation. Very recently, laser vision sensor becomes a useful sensing tool to find the seams. Until now, however studies of welding automation using a laser vision sensor, focused on either image processing or feature recognition from CCD camera. Even though it is possible to use a simple algorithm for tracking a simple seam, it is extremely difficult to develop a seam-tracking algorithm when the seam is more complex. To overcome these difficulties, this study introduces a simulation system to develop the seam tracking algorithm. This method was verified experimentally to reduce the time and effort to develop the seam tracking algorithm, and to implement the sensing device.

• Proceedings of the KIPE Conference
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• 2000.07a
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• pp.556-559
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• 2000

Pulse inverter-type TIG(Tungsten Inert Gas) arc welders are studied to investigate the dynamic performance of welding. Welding currents are controlled to be pulse waveforms resulting in stable are better welding performance. The hybrid-type controller is proposed to control the welding current. Todemonstrate the practical significance of our results we present some simulation results.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2006.11a
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• pp.193-196
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• 2006

Recently many research are going on in the field of application of Laser and Laser-Arc hybrid welding for superstructures such as ship-structures, transport vehicles etc. Therefore in this study an optimized welding condition and numerical simulation for hybrid welding by using previous numerical analysis which is used to calculate the heat source for Laser and Laser-Arc hybrid welding has been analyzed. For this purpose, fundamental welding phenomena of hybrid process(Laser+MIG) are determined based on the experiments. In order to calculate temperature and residual stress distribution in Laser and Laser-Arc hybrid welds, finite element heat source model is developed on the basis of experiment results and characteristics of temperature and residual stress distribution in Laser and Laser-Arc hybrid welds are understood from the result of simulation and found comparable to the experimental values.

• Journal of Welding and Joining
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• v.28 no.4
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• pp.55-60
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• 2010

The purpose of this paper is to propose a mathematical model of welding current for the P-GMAW by modifying the well known GMAW model. Welding power circuit is simply modeled as a RL electric circuit and solved as an ODE equation. The welding current depends on the joint shape, molten pool and welding parameters. To compare the molten pool effect to the welding current, CFD numerical simulation technique was adopted. Welding experiment is also conducted with the same welding parameters as used in numerical simulations to verify the proposed welding current model. The current model which is considered molten pool shape, is more fit to experiment result.

• Journal of Welding and Joining
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• v.16 no.6
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• pp.104-112
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• 1998

In the previous study, the countermeasure for welding deformation of bracket tilt is through up through experimental inspection for total process including welding process. For completeness of systematic examination of parts having sensitivity on welding deformation, the comparison and feedback between the result through simulation of welding process and experimental data is needed. In other words, it is necessary to control welding deformation that construct the prediction system for welding deformation through comparison and tuning with experimental data. In the present study, the application of FEA on welding process of bracket tilt with susceptibility to deformation is made and deformation behavior through change of welding sequence is focused on. It is used to improve the exactness of deformation analysis that three dimensional analysis for moving heat source, activated and deactivated bead element, and volume heat flux etc.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2008.10a
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• pp.267-270
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• 2008

Thermo-mechanical simulation of the friction stir butt welding process was performed for AA5083-H18 sheets, utilizing commercial FVM code, STAR-CCM+, which is based on Eulerian formulation. Temperature and strain rate histories along the material flow were calculated under the steady state condition and simulated temperature distributions (profiles and peak values) were compared with experiments for verification. It was found that by including proper thermal properties of the backing plate (anvil) the accuracy of the simulation results increased significantly.

• Proceedings of the KIPE Conference
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• 2001.10a
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• pp.731-736
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• 2001

Nowadays various simulation tools are widely used for the design and the analysis of power electronic converters. From the engineering point of view it is rather difficult to parameterize power semiconductor device models without the knowledge of basic physical parameters. In recent years some data sheet driven behavioral models or so called 'wizard' tools have been introduced to solve this problem. In this contribution some experiences with some user-friendly power semiconductor models will be discussed. Using special simulation test circuits it is possible to get information on the static and dynamic behavior of the parameterized models before they are applied in more complex schemes. These results can be compared with data sheets or with measurements. The application of these models for power loss analysis of inverter type arc welding power sources will be described.

• Proceedings of the KWS Conference
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• 2010.05a
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• pp.53-53
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• 2010

The purpose of this paper is to propose a mathematical model of welding current for the P-GMAW by modifying the well known GMAW model. Welding power circuit is simply modeled as a RL electric circuit and solved as an ODE equation. The welding current depends on the joint shape, molten pool and welding parameters. To compare the molten pool effect to the welding current, CFD numerical simulation technique was adopted. Welding experiment is also conducted with the same welding parameters as used in numerical simulations to verify the proposed welding current model. The current model which is considered molten pool shape, is more fit to experiment result.