HUNDREDS OF THOUSANDS of people work in welding, cutting and brazing. It is estimated that welders compose 1 to 2% of the U.S. working population, including a significant segment of the aging workforce. According to OSHA’s Christine Petitti, the most commonly used welding processes are: 1) Flux-cored arc welding (FCAW). This process uses an arc between a continuous filler metal electrode and th...

Overlay welding of nickel alloys for corrosive and sour service is commercially accomplished with most welding processes ranging from shielded metal arc (stick) to laser. The valve industry has generally standardized on hot wire gas tungsten arc (GTA-HW), pulsed gas metal arc (GMA-P) and submerged arc (SAW) welding. This document will focus on these three but a little history will help explain ...

Three-phase four-leg inverters are typically employed to supply unbalanced loads avoiding the use of a transformer. Usually, the inverter control is performed by modulation techniques, such as the threedimensional one, requiring complex mathematical algorithms. The paper suggests a different approach, based on the separation of the control of the fourth leg from that of the other phases, allowi...

A fault tolerant structure and its corresponding control strategy for electromagnetic stirring power supplies are proposed in this paper. The topology structure of the electromagnetic stirring power supply contains two-stages. The fore-stage is the PWM rectifier. The back-stage is the fault tolerant inverter, which is a two-phase three-bridge orthogonal inverter circuit while operating normally...

A new fiber sensor system designed for spectroscopic analysis and on-line quality assurance of arc-welding processes is presented here. Although several different approaches have been considered for the optical capture of plasma emission in arc-welding processes, they tend to be invasive and make use of optical devices such as collimators or photodiodes. The solution proposed here is based on t...

Recently, the serious problems facing heavy industries such as the increase in the average age of employees, shortage of skilled workers and environmental problems in the workplace are being addressed. The bridge panel fabrication system we have developed is such an approach to solve these problems. It consists of two parallel box girder panel sub-assembly lines, one exclusively for web panels ...

At present, the research on five-level inverters mainly involves the modulation algorithm and topology, and few articles study the five-level inverter from the control strategy. In this paper, the nonlinear passivity-based control (PBC) method is proposed for single-phase uninterruptible power supply inverters. The proposed PBC method is based on an energy shaping and damping injection idea, wh...

Due to the rapid growth of non-linear loads, such as power electronic control equipments and Electric arc furnace (EAF) power quality problems such as harmonics and voltage flicker are introduced in the power system. It occurs because of the time-varying and nonlinear behaviour of the Load. Arc furnaces are used in industries for induction heating and welding. Hence an Electric arc furnace mode...

ABSTRACT This paper proposes a sleep transistor based minimum size inverter in BSIM4.3.0, 50nm CMOS technology with supply voltage of 1V, power dissipation of 46.28nW at 0.502V and maximum drain current of 70nA. The operating frequency is kept at 1GHz, and found that it can be used up to 10GHz successfully. The reduction in power dissipation is 98.88% and operating frequency is almost 2 times t...

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...