<title>Burst phase-angle thermography with elastic waves</title>

Abstract

Defect selective non-destructive testing methods are increasingly being used for safety relevant applications in aerospace and related fields. The main advantage is the clarity in interpretation of such methods: defects are revealed while non- relevant structural information is suppressed. One way to achieve defect selectivity is the combination of mechanical load to generate heat inside a sample and thermography to detect the resulting thermal waves. Ultrasound Lock-in thermography is one example of an established defect selective testing method described previously. In this paper, several kinds of excitation sources and modulation shapes are discussed.