Understanding Infrared Thermography Reading 3

Typical failure modes of the material samples are(1) voids between layers, (2)
disbonds between layers, (3) impurities or foreign material in the laminar
interfaces and (4) significam irregularities (damage) to the geometric core
structure. Typical defects in assembled sections are loose or damaged welds
and rivets and erosion/corrosion between sections. often accompanied by
material loss and thinning.
Establishing test protocol involves determining acceptability of each part to be
evaluated in terms of minimum size of void to be detected, minimum area of
disbond that can be said to constitute a defect and any other void or disbond
characteristic that is deemed significant. For this it is necessary to use known
acceptable and known defective samples. Ideally, the defective samples
furnished should include known defects of each classification and in the
minimum sizes required to be detected and identified. When ideal defective
samples are not available. it becomes necessary to synthesize flaws to
simulate the minimum defects.
Charlie Chong/ Fion Zhang