NDTE using pulse thermography: Numerical modeling of composite subsurface defects

Depth Retrieval Procedures in Pulsed Thermography: Remarks in Time and Frequency Domain Analyses

“…Pulsed Thermography (PT) is a widely used technique for the Non-Destructive Testing and Evaluation (NDT&E) of advanced materials and structures [1][2][3][4][5]. Compared with other NDT&E technologies, this thermographic configuration presents remarkable benefits such as its rapid and simple implementation, its suitability for large-scale inspections and complex surface monitoring, as well as its contactless application requiring no physical contact to the material being inspected.…”

Development of Infrared Techniques for Practical Defect Identification in Bonded Joints

“…From these basic plate models it was stated that more complex geometries could be studied but no work was presented. A later paper by Krishnapillai et al [16] has shown that 2D FEA modelling of subsurface defects is inaccurate for contoured surfaces or complex geometries but may be suitable for flat plates. The present work described in the thesis focuses on flat plates or bonds and as such a 2D model is deemed suitable.…”

“…Previous numerical models developed to simulate PT have attempted to inform experimental data collection parameters, such as the duration of data collection required, or predict defect depth [15,16]. While some use is made 5 of these models it is the methods used to simulate defects within components that misses the complexity of a real defect.…”

“…Previous models tend to model defects as either flat bottom holes, e.g. [16,17] or areas of perfect insulation, e.g. [15].…”

Numerical simulations of thermographic responses in composites

“…Numerical techniques such as finite difference and finite element methods are well suited for such problems [2,3], but can be computationally intensive. Both commercial [4,5,6,7] and noncommercial [8,9] simulation packages have been successfully applied to simulating thermographic nondestructive evaluations. For simulation of flash heating, some care is required, since the application of short duration flux to the surface results in a large spatial gradient in the temperature at early times.…”