Open Access
Simultaneous In-Process Control of Heat-Affected Zone and Cooling Rate during Arc Welding A model is developed for independently regulating the time-temperature relationship of the HAZ and the centerline cooling rate
C. C. Doumanidis,D. E. Hardt +1 more
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TLDR
In this article, the problem of process con- trol in welding involves not only regulation of weld bead geometry, but also temperature induced changes such as distortion, residual stresses and metallurgical trans- formations near the weld.Abstract:
The problem of process con trol in welding involves not only regulation of weld bead geometry, but also ther mally induced changes such as distortion, residual stresses and metallurgical trans formations near the weld. This paper ad dresses the last of these, and poses it as a feedback control problem. The objective is transformed to one of controlling the surface temperature field in-process, and using temperature feedback to implement such a scheme. A control model of the process is presented, and a parameter adaptive controller is designed to ensure consistent control system performance. A series of numerical simulations and exper iments using CMA welding is presented that confirms the model and illustrates the desired properties of the controller. With this system, the heat-affected zone and cooling rate (through their correlates in surface temperature-time relationships) can be regulated independent of each other, and gross disturbances to the tem perature field rejected totally in the steady- state. In addition, dynamic performance of the control system is illustrated, and the limits imposed by current hardware are discussed.read more
Citations
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Infrared thermography for condition monitoring – A review
TL;DR: This review focuses on the advances of IRT as a non-contact and non-invasive condition monitoring tool for machineries, equipment and processes.
Journal ArticleDOI
Infrared sensing techniques for penetration depth control of the submerged arc welding process
TL;DR: In this article, a rugged, low-cost, point infrared sensor was used to monitor changes in the plate surface temperatures occurring during the welding process to eliminate or mitigate defects that may form due to the process perturbations.
Journal ArticleDOI
Multipredictive adaptive control of arc welding trailing centerline temperature
TL;DR: Experimental results presented include characterization of plant uncertainty and of the effect in control performance of various available knobs, in particular in the presence of plates with variable geometry.
Journal ArticleDOI
Multiplexed and distributed control of automated welding
TL;DR: In this paper, a continuous heat distribution and temperature monitoring on the entire weld surface is adopted to maximize the range of achievable weld features, and the necessary vector-scanning trajectories of the torch are regulated in real time by a distributed-parameter control strategy, integrated to the weld design software.
Thermography for Online Detection of Incomplete Penetration and Penetration Depth Estimation
Baldev Raj,Indira Gandhi +1 more
TL;DR: In this article, the authors highlight the application of thermal imaging sensors for detection of defects such as lack of penetration and estimation of depth of penetration during Tungsten Inert Gas (TIG) welding.
References
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Book
Conduction of Heat in Solids
H. S. Carslaw,John Conrad Jaeger +1 more
TL;DR: In this paper, a classic account describes the known exact solutions of problems of heat flow, with detailed discussion of all the most important boundary value problems, including boundary value maximization.
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Discrete-time multivariable adaptive control
TL;DR: In this paper, the authors established global convergence for a class of adaptive control algorithms applied to discrete time MIMO deterministic linear systems and showed that the algorithms will ensure that the system inputs and outputs remain bounded for all time and that the output tracking error converges to zero.
Journal ArticleDOI
Mechanical Behavior of Materials
TL;DR: In this article, the authors describe the behavior of materials in terms of Mechanical behavior of Materials and Mechanical Behavior of Materials (MBE) of materials, including the following types of materials:
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A numerical thermo-mechanical model for the welding and subsequent loading of a fabricated structure
Hugh D. Hibbitt,Pedro V. Marcal +1 more
TL;DR: In this article, a numerical model is developed for the welding and subsequent loading of a fabricated structure, which treats the weld process as a thermo-mechanical problem, and the model includes finite strain effects during isothermal loading, so that it may be used in the modeling of distortion sensitive structure.