Study of multi-long-pulse thermography using high-power fiber lasers

Abstract

Active infrared thermography tests are performed using a high-power continuous fiber laser as the excitation source. Multi-long-pulses (MLPs) are used to detect deep defects in samples with reduced heating. Simulation results are compared to theoretical predictions based on 1D heat conduction equations. Different excitation modes are compared. Thermal images are processed using pulsed phase thermography and principal component thermography (PCT), showing that the combination of MLP thermal excitation and PCT data analysis provides better defect detection capability and reduces the specimen’s surface temperature in comparison to conventional pulsed thermography.