Thermographic identification of defects in adhesively bonded joints

Abstract

The potential use of pulse phase thermography (PPT) and thermoelastic stress analysis (TSA) to identify artificial defects in CFRP single lap joints has been studied. PPT was able to identify defects in adhesive bonds where there was a contrast between defect and non-defect thermal properties. Where a lack of thermal contrast occurred it was found that the application of a small load was sufficient to reveal a previously unidentified defect. TSA was able to reveal defects where there was a change in stress distribution caused by the defect; however it did not identify inclusions that had very little effect on stress distributions. It may be argued that such an inclusion is not a defect. It is necessary to clarify this as false identification of defects may lead to unnecessary repair work. © The Society for Experimental Mechanics, Inc. 2014.