Predictability of surface temperatures from FE calibrated thermal constants

A method is being developed and calibrated where remote sensing can be used to provide information on surface cracks. This will allow the extent of possible degradation to be evaluated. Initially, a perfect specimen (such as concrete) in an unstressed condition is subjected to Active Thermographic Approach (ATA) to monitor its surface temperature profiles. Finite Element (FE) and Inverse Analyses (lA) are then used to calculate the in-situ thermomechanical constants based on experimental thermal fields. As follow-on, a number of specimens with specified values of crack geometry (modeling damage) are examined thermographically. The surface temperature variations are recorded for subsequent lA. Therefore, it has been possible to calibrate a predictive FE model, so that the observed experimental temperature variation is replicated numerically. From non-invasive and non-contact damage detection viewpoint, the present authors have already reported a fault monitoring distance of 20 m relating to a fault on an RC beam soffit. Additionally, they could detect a crack-tip temperature variation corresponding to a concrete discontinuity of 0.1 mm from a distance of 2.0 m.