Noncontact Ultrasonic Sensing for Seam Tracking in Arc Welding Processes

1998 ◽  
Vol 120 (3) ◽  
pp. 600-608 ◽  
Author(s):  
S. B. Zhang ◽  
Y. M. Zhang ◽  
R. Kovacevic
Keyword(s):  
Arc Welding ◽  
Focal Length ◽  
Tracking System ◽  
Gas Metal Arc Welding ◽  
Transmission Efficiency ◽  
Seam Tracking ◽  
High Frequency Ultrasound ◽  
Tracking Accuracy ◽  
Metal Arc Welding ◽  
Welding Processes

A novel seam tracking technology based on high frequency ultrasound is developed in order to achieve high accuracy in weld seam identification. The transmission efficiency of the ultrasound is critical for obtaining a sufficient echo amplitude. Since the transmission efficiency is determined by the difference in impedance between the piezoelectric ceramic and air, match layers are designed to optimize the transmission efficiency by matching impedance. Since the air impedance depends on the density and velocity of the ultrasound, which both depend on the temperature, the optimization has been done for a wide bandwidth. Also, the receiving circuit is designed so that its resonance frequency matches the frequency of the ultrasound. As a result, the sensitivity of the noncontact ultrasonic sensor is improved 80-fold. By properly designing the focal length of the transducer, a high resolution ultrasound beam, 0.5 mm in diameter, is achieved. Based on the proposed sensing technology, a noncontact seam tracking system has been developed. Applications of the developed system in gas tungsten arc welding (GTAW) and CO2 gas metal arc welding (GMAW) processes show that a tracking accuracy of 0.5 mm is guaranteed despite the arc light, spatter, high temperature, joint configuration, small gap, etc.

A study on an automatic seam tracking system by using an electromagnetic sensor for sheet metal arc welding of butt joints

2002 ◽  
Vol 216 (6) ◽  
pp. 911-920 ◽  
Author(s):  
B-H You ◽  
J-W Kim
Keyword(s):  
Sheet Metal ◽  
Arc Welding ◽  
Tracking System ◽  
Weld Line ◽  
Welding Process ◽  
Seam Tracking ◽  
Displacement Sensor ◽  
Tracking Accuracy ◽  
Metal Arc Welding ◽  
Electromagnetic Sensor

Many sensors, such as the vision sensor and the laser displacement sensor, have been developed to automate the arc welding process. However, these sensors have some problems due to the effects of arc light, fumes and spatter. An electromagnetic sensor, which utilizes the generation of an eddy current, was developed for detecting the weld line of a butt joint in which the root gap size was zero. An automatic seam tracking system designed for sheet metal arc welding was constructed with a sensor. Through experiments, it was revealed that the system had an excellent seam tracking accuracy of the order of ±0.2mm.

A study on sustainability assessment of welding processes

2019 ◽  
Vol 234 (3) ◽  
pp. 501-512 ◽  
Author(s):  
Jaber Jamal ◽  
Basil Darras ◽  
Hossam Kishawy
Keyword(s):  
Arc Welding ◽  
Social Impact ◽  
Sustainability Assessment ◽  
Gas Metal Arc Welding ◽  
Welding Process ◽  
Friction Stir ◽  
Gas Tungsten Arc ◽  
Metal Arc Welding ◽  
Sustainability Assessments ◽  
Welding Processes

The concept of “sustainability” has recently risen to take the old concept of going “green” further. This article presents general methodologies for sustainability assessments. These were then adapted to measure and assess the sustainability of welding processes through building a complete framework, to determine the best welding process for a particular application. To apply this methodology, data about the welding processes would be collected and segregated into four categories: environmental impact, economic impact, social impact, and physical performance. The performance of each category would then be aggregated into a single sustainability score. To demonstrate the capability of this methodology, case studies of three different welding processes were performed. Friction stir welding obtained the highest overall sustainability score compared to gas tungsten arc welding and gas metal arc welding.

Tandem laser-gas metal arc welding joining of 20 mm thick super duplex stainless steel: An experimental and numerical study

2020 ◽  
Vol 234 (5) ◽  
pp. 697-710
Author(s):  
A Mathieu ◽  
I Tkachenko ◽  
JM Jouvard ◽  
I Tomashchuk
Keyword(s):  
Numerical Simulation ◽  
Heat Source ◽  
Laser Beam ◽  
Arc Welding ◽  
Gas Metal Arc Welding ◽  
Image Correlation ◽  
Angular Distortion ◽  
Metal Arc Welding ◽  
Welded Structure ◽  
Welding Processes

The present work covers the topic of strains and stresses prediction in case of welded steel structures. Steel sheets of 20 mm thickness made in UR™2507Cu are welded using a laser and gas metal arc welding processes combination. The focused laser beam leads the arc in a Y-shape chamfer geometry. Both sources are 20 mm apart from each other in order to avoid any synergic effect with each other. In order to predict residual strain, a 3D unsteady numerical simulation has been developed in COMSOL finite element software. A volume heat source has been identified based on the temperature measurements made by 10 K-type thermocouples, implanted inside the workpiece. The 50 mm deep holes are drilled in the workpiece using dye-sinking Electrical Discharge Machining (EDM) machine. Before the implantation in the hole, each thermocouple is surrounded by Inconel sheathing. Hot junctions of the thermocouples are positioned in a way to feel two advancing molten pools. The equivalent heat source is composed of three sources. First one is a Goldak source that represents the molten pool induced by gas metal arc welding. The second one is a cylinder with an elliptic cross-section that represents the focused laser beam penetrating into the workpiece. The third one is a surface Gaussian source that represents energy radiated by arc and blocked by workpiece surface. Concerning mechanical simulation, an elasto-plastic behavior with isotropic hardening is implemented. A weak coupling is established between equations governing heat transfer and mechanics thanks to the temperature dependent coefficient of linear expansion. This numerical simulation made with some simplifying assumptions predicts an angular distortion and a longitudinal shrinkage of the welded structure. The numerical results are consistent with the displacements measured by digital image correlation method.

scholarly journals An adaptive approach to compensate seam tracking error in robotic welding process by a moving fixture

2018 ◽  
Vol 15 (6) ◽  
pp. 172988141881620
Author(s):  
Reza Ebrahimpour ◽  
Rasul Fesharakifard ◽  
Seyed Mehdi Rezaei
Keyword(s):  
Weld Pool ◽  
Arc Welding ◽  
Sliding Mode ◽  
Gas Metal Arc Welding ◽  
Tracking Error ◽  
Welding Process ◽  
Seam Tracking ◽  
Ball Screw ◽  
Robotic Welding ◽  
Metal Arc Welding

Welding is one of the most common method of connecting parts. Welding methods and processes are very diverse. Welding can be of fusion or solid state types. Arc welding, which is classified as fusion method, is the most widespread method of welding, and it involves many processes. In gas metal arc welding or metal inert gas–metal active gas, the protection of the molten weld pool is carried out by a shielding gas and the filler metal is in the form of wire which is automatically fed to the molten weld pool. As a semi-metallic arc process, the gas metal arc welding is a very good process for robotic welding. In this article, to conduct the metal active gas welding torch, an auxiliary ball screw servomechanism is proposed to move under a welder robot to track the welded seam. This servomechanism acts as a moving fixture and operates separately from the robot. At last, a decentralized control method based on adaptive sliding mode is designed and implemented on the fixture to provide the desired motion. Experimental results demonstrate an appropriate accuracy of seam tracking and error compensation by the proposed method.

Advanced gas metal arc welding processes

2012 ◽  
Vol 67 (1-4) ◽  
pp. 655-674 ◽  
Author(s):  
P. Kah ◽  
R. Suoranta ◽  
J. Martikainen
Keyword(s):  
Arc Welding ◽  
Gas Metal Arc Welding ◽  
Metal Arc Welding ◽  
Welding Processes
Sign in / Sign up

Export Citation Format

Share Document