Taking into account heat losses in front-face pulse IR thermography experiment for thermal diffusivity identification

Abstract

Thermal diffusivity can be measured by analysing the pulse response of the rear-face or of the front-face using a single detector or an IR camera. For the front-face configuration a simple identification method is proposed in the case of significant heat losses. The method is based on original correlations established between the occurrence times and values of the first and second logarithmic derivatives obtained by the thermographic signal reconstruction (TSR) method. The intrinsic accuracy of the identified diffusivity is evaluated by numerical simulations and validated by the analysis of experimental thermograms. Guidelines are proposed to optimise the identification procedure.

Applying a Two-Layer Quadrupole Model for Quantitative Thermography at Overload-Induced Delaminations in GFRP

“…When investigating deeper defects in material with low heat conduction, convectional heat losses alter the TSR and PPT signals and cannot be neglected. Some extensions considering these points exist [4]. The quantitative evaluation of PPT in terms of defect depth requires a scaling variable.…”