Real-time Weld Process Monitoring

Welding is a complex process, is increasingly automated, and operates at higher speeds in more difficult environments. Defects also need to be detected as they arise to ensure efficient, high-quality production. All these needs have led to a growing interest in the use of sensors to provide accurate, robust, real-time monitoring where this cannot be achieved by more traditional testing and inspection techniques. This important book reviews the range of monitoring techniques available and their applications.

After an introductory chapter, the first part of the book reviews the range of sensor technologies in welding, from arc and optical sensors to infrared and ultrasonic techniques. Part two discusses the monitoring of particular aspects of welding such as weld seams and profiles, the analysis of weld penetration and weld pool surface, as well as monitoring of resistance and laser welding.

Table of Contents

 

PART 1 MONITORING TECHNOLOGIES
Arc sensors in weld monitoring
Introduction.
Background.
Non-consumable electrode processes.
Consumable electrode processes.
Power supply considerations.
Signal processing and control approaches.
Future trends.
Sources of further information and advice.
Appendix: List of symbols.
Optical sensors in welding
Introduction.
Knowledge of optics.
Optical sensor component.
Optical sensing system.
Application of optical sensor.
Infrared sensors in welding
Introduction.
Theory of infrared sensors.
Measurement of weld temperature distribution.
Infrared sensors for real-time weld quality control.
Weld position control.
Cooling rate.
Ultrasonic sensors in welding
Introduction.
Principles of ultrasonic sensing.
Ultrasonic techniques and their applications.
Future trends.
PART 2 MONITORING OF WELDING PROCESSES
Weld seam monitoring
Introduction.
Methods of weld seam monitoring.
Through-arc monitoring of weld seams in gas metal arc welding.
Electromagnetic monitoring of weld seams in gas metal arc welding.
Laser visual monitoring of weld seams in gas metal arc welding.
Weld profile monitoring
Necessity for weld profile measurement.
Outline of weld profile.
Surface shaping defects.
Automatic detection of weld profile.
Weld penetration monitoring
Introduction.
Weld pool oscillation sensor.
Infrared sensor.
Ultrasonic sensor.
Vision based sensor.
Weld pool sag depression.
Plasma charge based sensors.
Weld penetration control using sensor feedback.
Weld pool surface monitoring
Vision-based sensing 2-D surface geometry of weld pool in GTAW.
Sensing 2-D weld pool boundary in GMAW.
Modeling and simulation of weld pool surface.
Sensing 3-D weld pool surface using specular reflection.
Improvement on observation of dynamic 3-D weld pool surface.
Monitoring resistance welding
Introduction.
Resistance spot welding (RSW) systems, weld formation and signals.
Real-time process monitoring and control.
Future trends.
Monitoring laser welding
Introduction.
Principles of laser welding.
Optical sensing.
Frequency analyses of acoustic and optical emissions.
Smart systems.
Other systems and future trends

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