Strain and distortion monitoring during arc welding by 3D digital image correlation

ABSTRACT

A novel three-dimensional (3D) digital image correlation (DIC) approach using a stereovision system was developed to measure the evolution of strain and distortion near the fusion zone during the gas tungsten arc welding process. Unlike the previously reported two-dimensional (2D) DIC approach using a single camera, the 3D DIC method was immune to the out-of-plane displacement and was capable of measuring 3D deformation. Both 2D and 3D DIC approaches in welding applications were based on the utilisation of the novel high-temperature speckle and the pulsed laser illumination plus bandpass filters. However, the speckle pattern was partially specular reflective causing issues in subset matching in the 3D approach. A new algorithm and experimental procedure was incorporated to solve this problem.

KEYWORDS:

• Welding
• distortion
• strain
• digital image correlation
• binocular stereovision
• specular reflection

Acknowledgement

The authors would like to thank Dr Yanli Wang for the help on experiments. We would also like to acknowledge Dr Stan A. David for his review and valuable comments.

This manuscript has been authored by UT-Battelle, LLC under Contract No. DE-AC05-00OR22725 with the U.S. Department of Energy. The United States Government retains and the publisher, by accepting the article for publication, acknowledges that the United States Government retains a non-exclusive, paid-up, irrevocable, worldwide license to publish or reproduce the published form of this manuscript, or allow others to do so, for United States Government purposes. The Department of Energy will provide public access to these results of federally sponsored research in accordance with the DOE Public Access Plan (http://energy.gov/downloads/doe-public-access-plan).

Disclosure statement

No potential conflict of interest was reported by the authors.

Notes

1 Specular reflection is a mirror-like reflection of light with the reflected beam having the same angle to the incident beam. On the contrary, diffusive reflection is scattered with a range of directions.

Additional information

Funding

This research was sponsored by the U.S. Department of Energy, Office of Nuclear Energy, for Nuclear Energy Enabling Technologies Crosscutting Technology Development Effort, under a prime contract with Oak Ridge National Laboratory (ORNL). ORNL is managed by UT-Battelle, LLC for the U.S. Department of Energy under Contract DE-AC05-00OR22725.