|Budget Amount *help
¥2,100,000 (Direct Cost : ¥2,100,000)
Fiscal Year 1997 : ¥600,000 (Direct Cost : ¥600,000)
Fiscal Year 1996 : ¥1,500,000 (Direct Cost : ¥1,500,000)
In this work, a feasibility study has been conducted to determine if a numerical model can be used for optimizing laser or arc welding processes.
In the first part of this work, a mathematical model of welding process has been discussed, where the equation of heat conduction is numerically analyzed to estimate the molten pool size in welding, and a surface tensional balance equation is solved numerically to obtain the molten pool surface profile in welding. As a result of the comparison between model analysis and experiment on laser or arc welding, it is made clear that the numerical model, developed in this work, is a useful tool for the simulation of laser or arc welding process.
In the second part of this work, the radiation thermometry has been applied to monitor the temperature field in laser or arc welding process.The reliability of the thermometry is, however, limited under the condition that the emissivity of the work to be measured is not accurately known as in the case of laser or arc welding process.
In order to avoid the above emissivity problem, an UV (ultra-violet) radiation thermometry has been proposed and discussed experimentally. A measuring system of CCD camera with UV-filter, used in the present work, made it possible to detect the temperature image on the plate in welding without any emissivity correction.
It is concluded that a model reference control system of welding is possible by using the model and the UV radiation thermometry developed in this work.