Researchers at NASA Johnson improved their flash thermography capabilities by incorporating transient and lock-in thermography to their flash thermography NDE technology. This non-destructive evaluation (NDE) technology identifies flaws in materials used in airplanes, drones, and buildings.
By adding the transient thermography method, which detects flaws on thicker parts faster than other methods, and the lock-in thermography method, which uses a sinusoidal power cycle to provide a better flaw resolution, the flash thermography NDE technology suite has expanded its applicability to other commonly used infrared thermography techniques.
When using the transient and lock-in methods to evaluate materials, variations in the thermal diffusivity of the material manifest themselves as anomalies in the infrared (IR) image of the test surface. Both methods are specifically used to analyze thicker material than is possible by flash thermography alone. Post-processing of this raw IR camera data provides detailed analysis of the size and characterization of anomalies.
This technology includes a software that offers highly precise measurements.
The peak contrast and peak contrast time profiles generated through this tool provide quantitative interpretation of the images including detailed information about the size and shape of the anomalies. The persistence energy and persistence time profiles provide highly sensitive data for detected anomalies. Peak contrast, peak time, persistence time, and persistence energy measurements also enable monitoring for flaw growth and signal response to flaw size analysis.
This technology provides more comprehensive, detailed, and accurate NDE detection and characterization of subsurface defects in nonmetallic composite materials than current methods. This complete software suite normalizes and calibrates the data, which provides more stable measurements and reduces the occurrence of errors due to operator and camera variability.