This paper describes a method for non-destructive evaluation of the quality of welds from 3D point data. The method uses a stereo camera system to capture high-resolution 3D images of deposited welds, which are then processed in order to extract key parameters of the welds. These parameters (the weld angle and the radius of the weld at the weld toe) can in turn be used to estimate the stress co...

Visual sensing technology is widely used in welding practices because visual devices are decreasing in price, increasing in reliability and improving in image processing hardware and software. As the most studied welding sensor, CCD(Charge Coupled Device) is more suitable for quality control of welding process than other means of sensing devices because it can obtain both two dimensional and th...

In December 2006, the Boiling Water Reactor Vessel and Internals Project (BWRVIP) issued a letter mandating two-sided coverage for the volumetric examination of BWR core shroud welds. In this letter, they noted that: “Ultrasonic flaw detection and sizing performance is degraded by stainless steel or nickel allow weld metal. The base metal examination volumes on both sides of the weld should be ...

Stable weld formation is still one of the goals pursued in variable-polarity plasma arc welding (VPPAW) of aluminium alloys. Basically, VPPAW is divided into three segments: the startup segment, during which the keyhole is generated, the main body segment, during which the keyhole is dynamically maintained, and the terminal segment, during which the keyhole collapses and the crater is ®lled. Ve...

Long-term changes in the seasonal timing of phytoplankton and zooplankton population development (i.e. phenological changes) have been widely reported in freshwater and marine ecosystems, and have been interpreted as a biological response to ongoing climate change. Observed among-species variations in the rates and patterns of these changes have led to concerns that seasonal trophic interaction...

Duplex stainless steel multi-pass welds were made at 0.15 MPa, 0.45 MPa, and 0.75 MPa pressure, simulating underwater dry hyperbaric welding by the flux-cored arc welding (FCAW) method, with welds of normal pressure as a benchmark. The purpose of this work was to estimate the effect of ambient pressure on the microstructure, pitting corrosion resistance and impact toughness of the weld metal. T...

Metamer mismatching has been previously found to impose serious limitations on colour constancy. The extent of metamer mismatching is shown here to be considerably smaller for trichromats than for dichromats, and maximal for monochromats. The implications for achromatic colour perception are discussed.

The present work demonstrates that friction stir welding (FSW) is a feasible route for joining 6061 aluminium (Al) alloy to AISI 1018 steel. The weld has a good weld quality and is free of cracks and porosity. The tensile failure happened at the boundary between the nugget and thermomechanically affected zone of the base Al alloy, indicating that the weld has a higher joining strength. Despite ...

Gas Metal arc Welding (GMABQ has become the most addely used process for joining of steel plates due to its high productixity, simplicity of equipment and ease of use. Although the process of melting of the electrode and development of the weld deposit has been studied for 40 years, the dynamic nature of the process has not been studied in detail because accurate models are computationally inte...

In ultrasonic welding, high frequency vibrations are combined with pressure to join two materials together quickly and securely. Ultrasonic welding can join dissimilar metals in a split second, ultrasonic welding eases problematic assembly and this cost effective technique may be key to mass producing fuel efficient. In this work effect of various parameters on weld strength have been studied. ...