Introduction. Multilayer structures have a high stiffness with low weight. The rigidity of the structures can be preserved only under condition of their integrity preservation. To identify emerging defects, there are different non-destructive testing methods and means. Increased use of composite materials leads to the development of new technologies for their inspection. The thermal inspection is a method preferred for defect detection in multilayer structures. Method. The article presents a study on application of thermal method for testing of composite multilayer structures to enhance the testing efficiency. Using a mathematical model of thermal testing, the theoretical studies of defect detection possibility (POD) were carried out on the basis of temperature fields’ analysis. The values of varied factors, which provide the best detection of defects, were determined. The results of mathematical modelling served as a basis for the experimental research to determine the capabilities of the thermal method to detect defects. Results. The experimental results were used to develop the inspection technique and hardware for defective areas identifying in the aircraft fairings. The developed technique helped to increase the reliability of the air fairing testing by 7% and efficiency by 40% (for labour costs).
technical condition, multilayer element, aircraft construction, border of the defect, temperature contrast
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