Optimization of thermographic NDT using finite element analysis

Experimental and analytical methods were used to study heating techniques for IR thermography inspection of superplastic formed/diffusion bonded (SPF/DB) structural components. Various thermal loads were investigated to determine the parameters required for highest flaw detection sensitivity. Finite element analysis was used to determine optical heating techniques. According to the analysis, short burst, high intensity heating on the inspection side of the part is required for the highest flaw detection sensitivity. The analytical results were verified using an IR camera and heat lamps to detect unbonds in four-sheet SPF/DB panels. Good quantitative agreement between the analysis and laboratory experiments was obtained.