Applications of Infrared Thermography to the Analysis of Steel Welded Junction

Abstract

The thermographic methodology based on the analysis of the response of the materials after an external stimulation can be used as a tool for the detection, characterization and evaluation of surface cracks in steel welds. These types of cracks are usually difficult to detect and their dangerousness could be a problem for the integrity of welded elements in machines and structures. Several studies have demonstrated the usefulness of the thermographic technique for the assessment of composites and metallic materials. However, the study of cracks in welds is a topic which has only been addressed in recent times. The thermographic technique, in combination with different processing algorithms allows the efficient detection of surface cracks in welds. If the procedure is complemented with the geometric calibration of the infrared camera, the accurate measurement of the surface dimensions of the cracks can be performed. What is more, the generation of the depth-prediction model of the cracks is possible through the correlation of the thermographic data with the three-dimensional data obtained using the macro-photogrammetry technique