An approach for modelling thermo-mechanical responses in a 3D arc welding process is developed using the Smoothed Particle Hydrodynamics (SPH) method. It is demonstrated for a simple arc welding configuration by using full three-dimensional elastoplastic analysis. The flow pattern of the filler material and the resulting plastic strain distribution are analysed. The effect of welding speed on t...

The objective of this study was to characterize personal exposures to welding-related metals and gases for production welders and non-welders in a large manufacturing facility. Welding fume metals and irritant gases nitrogen dioxide (NO2) and ozone (O3) were sampled for thirty-eight workers. Personal exposure air samples for welding fume metals were collected on 37 mm open face cassettes and ni...

We investigated relationships between occupational exposure to gas and arc welding fumes and the risk of lung cancer among workers exposed to these agents throughout the spectrum of industries. Two population-based case-control studies were conducted in Montreal. Study I (1979-1986) included 857 cases and 1066 controls, and Study II (1996-2001) comprised 736 cases and 894 controls. Detailed job...

An adaptive control based on fuzzy logic has been implemented for Gas Tungsten Arc Welding (GTAW). This adaptive controller eliminates the problems frequently experienced with traditional Automatic Voltage Control (AVC) systems, which do not adequately perform for all operational conditions because of the non-linear relationship between the arc voltage, current and arc length. This paper examin...

In the present study, the fumes generated from manual metal arc (MMA) and submerged metal arc (SMA) welding of low temperature service steel, and the chromium and nickel percentages in these fumes, were measured at various horizontal distances and vertical heights from the arc in order to obtain a three dimensional distribution. The MMA welding fume concentrations were significantly higher than...

Observation of the weld pool provides an effective path to understand and control the welding process. Observation data also attribute to the validation of numerical models, which helps researchers to analyze and evaluate the welding process. Extensive research has been conducted to provide in situ monitoring of the weld pool. The arc sensor was one of the first few sensors that was adopted for...

Predicting and controlling residual stresses are critical issues in welding engineering. With advancements in computer technology, a numerical simulation technique can predict welding residual stress. To accurately simulate temperature and stress fields, the thermal cycle obtained from the finite element model must be in coincidence with an actual heat source. This study performed a Gaussian di...

In regular arc welding, the arc heat is transferred from the surface of the workpiece to melt it. In keyhole plasma arc welding, the workpiece is melted by the plasma jet which heats the wall of the keyhole along the thickness direction. Penetration is achieved with reduced heat input. However, the plasma jet only gains its energy in the arc before reaching the keyhole. In the keyhole where no ...

This paper gives a recent progress of welding process research in Japan, especially, an instance in the capability of the visualization and prediction of welding arcs, though the dynamic observations of spectral image by a high-speed digital video-camera with a monochromator and also the calculations by numerical models. The dynamic observations lead to visualizations of metal vapor behavior in...

Sensing plays a key role in automating and controlling welding processes. Although arc light sensing has advantages over through-the-arc sensing for arc length control and seam tracking, the current technology relies on experimental data and lacks theoretical foundation. To improve measurement accuracy, this work addresses the theoretical foundation for arc light sensing. A theoretical model ha...