Integration of Thermographic Data into 3D Component Models for Defect Localization and Data Migration into the Digital Twin

Abstract

Lock-in thermography (LIT) is an established non-destructive testing method for detecting surface and near-subsurface defects based on amplitude and phase information. However, the resulting measurement data are typically available as two-dimensional image information, which limits the direct geometric assignment of detected anomalies within three-dimensional component geometries. Particularly in the context of digital twins and model-based condition assessment, there is therefore a need for methods for the spatial integration of thermographic measurement data into virtual component models. In this work, a software-based approach is presented that interprets lock-in thermography data as scalar surface fields and projects them onto three-dimensional stereolithography (STL) component models. Amplitude or phase values are normalized, converted into parametric quantities, and used to generate a 3D relief that visualizes the spatial distribution of the thermal response on the real component geometry. The method enables an intuitive geometric localization of thermographically detected defects and provides a flexible interface between thermographic measurement data acquisition and digital component representation.