This article provides a thermal analysis of scan welding, as a redesign of classical joining methods, employing computer technology to ensure the composite morphologic, material and mechanical integrity of the joint. This is obtained by real-time control of the welding temperature field by a proper dynamic heat input distribution on the weld surface. This distribution is implemented in scan welding by a single torch, sweeping the joint surface by a controlled reciprocating motion, and power adjusted by feedback of infrared temperature measurements in-process. An off-line numerical simulation of the thermal field in scan welding is established, as well as a linearized multivariable model with real-time parameter identification. An adaptive thermal control scheme is thus implemented and validated both computationally and experimentally on a robotic Gas-Tungsten Arc Welding setup. The resulting productivity and quality features of scan welding are comparatively analyzed in terms of material structure and properties of the joint.

Issue Section:
Research Papers
Topics:
Control modeling, Materials processing, Welding, Arc welding, Composite materials, Computer simulation, Computer technology, Feedback, Heat, Joining, Real-time control, Reciprocating motion, Robotics, Temperature, Temperature measurement, Thermal analysis, Tungsten
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