Preliminary Results

Abstract

The current chapter covers the preliminary work that was undertaken to investigate the range of defect identification possible with pulsed thermography (PT) and pulse phase thermography (PPT). Preliminary tests were carried out on simple geometry samples containing thermally contrasting simulated defects, i.e. not kissing defects. A variety of test specimens have been manufactured starting with single isotropic materials to orthotropic materials to adhesive bonds incrementally building the complexity of the heat transfer. A base line study using aluminium with flat bottom hole style defects was initially carried out as an introduction to the technique in an isotropic material. Initial samples using orthotropic composite materials focused on manufacturing materials with insert style defects. Bonded samples were then created with the addition of insert style defects to develop experience in testing bonded joint configurations. In all samples experimentally simulated defects were spaced sufficiently so that they could be studied individually, without interference from surrounding defects.