Project information

Project title: "Standardisation of defect dimensioning procedure by active infrared thermography"

The project is financed from state budget funds allocated by the Minister of Education and Science under the Polish Metrology II program.

Project number PM-II/SP/0003/2024/02

Grant amount 910,690.00 PLN

Total project amount 910,690.00 PLN

Place of implementation: Faculty of Electrical Engineering, Częstochowa University of Technology

Implementation period January 1, 2024 - December 31, 2025

Project implemented in agreement with the Central Office Measures

Project summary

     Infrared thermography is the primary method of measurement when, due to the specifics of the process or life-threatening danger to the person performing the diagnostic test, it is not possible to use classical contact methods. Such difficult objects are, for example: parts of rotating machinery, live equipment, objects at heights, metallurgical and heat treatment processes, chemical processes, etc. Thermographic diagnostics is used by many companies to evaluate anomalies in failure-prone areas, while in the defectoscopy of latent defects the use of thermography is quite limited due to the lack of widely accepted (with a few exceptions) standards and norms. Active thermography, in addition to determining the temperature distribution, offers the possibility of determining selected characteristics of the objects under examination. It involves analyzing over time the temperature changes of an object during the heating or cooling phase. For objects composed of different materials or homogeneous material containing internal defects, the nature of temperature changes will be different than for homogeneous material. This provides an opportunity to detect such inhomogeneities and determine their size and location, such as the depth at which the defect is located in the object under study. In addition, the nature of this defect can be determined. Typical types of defects that can be detected are metallic and non-metallic inclusions, cracks, delaminations that reduce the mechanical strength of materials, including electrotechnical and electronic materials. 

There are many methods of thermal forcing, algorithms for data analysis supported by numerous publications, but there is a noticeable lack of research in the direction of trying to standardize the test procedure. There are no known computational ways to determine the size of detected inhomogeneities, which can be considered universal and fully reliable, and therefore suitable for use in industrial measurements. The methodology for estimating the uncertainty of defect sizing based on the analysis of a sequence of thermograms obtained by active thermography also remains a research problem.

Project description

     The aim of the project is to propose an effective and robust measurement procedure for non-destructive testing of selected materials and objects, mainly used in the aviation and transport industries. The measurement procedure will be used to detect defects in the structure of the tested material and to determine their location and number based  on the analysis of a sequence of thermograms. The R&D tasks is to determine measurement conditions, select equipment and the metod of automatic analysis, interpretation and reporting of measurement data so that the method can be used in laboratory and industrial conditions.

Specific objectives

• Development of a series of reference materials with the properties and geometry of typical real materials and defects tested by active thermography; the reference materials will be used for calibration and adjustment of the measurement stand to detect inhomogeneities in the structure of homogeneous, multi-layered or internally non-homogeneous materials.
• Development and formalisation of the measurement procedure, including the method of analysis and interpretation of measurement data and uncertainty estimation.
• Construction of a prototype of a measurement station for the detecting and characterizing  defect parameters using the active thermography method with the developed and implemented measurement procedure.
• Checking the correctness of the method on material samples with know defects.
• Determining the limitations of the proposed measurement procedure and the scope of its applicability in laboratory and industrial conditions.
• Development of recommendations for the measurement procedure, i.e. conditions for conducting such measurements, selection of equipment, data analysis and conclusions in terms of dissemination and potential commercialization.
• Development of demonstration software for the analysis and interpretation of thermogram sequences.