Pulsed Infrared Thermography for Detecting Adhesive Lack in Composite Assemblies

This study investigates the maximum detection depth of adhesive defects in Carbon Fiber-Reinforced Polymer (CFRP) composite pipe assemblies using pulsed infrared thermography. The originality of this research lies in its innovative approach to enhancing the technique's capability to detect internal defects at greater depths. This is achieved through a thorough and systematic analysis of critical experimental parameters, particularly the duration and energy of thermal excitation, with the aim of optimizing defect detection performance. A composite assembly model was developed, featuring defects at depths ranging from 4 mm to 12 mm. The thermal responses were systematically evaluated using thermal image visualization, surface temperature variation measurements, and thermal contrast evolution analysis for each configuration. The results demonstrate that by carefully optimizing experimental parameters, defects can be detected at depths of up to 10 mm, significantly exceeding the conventional 5 mm limit associated with this technique. These findings underscore the enhanced potential of pulsed infrared thermography as a reliable and effective method for non-destructive testing of composite materials, offering improved detection capabilities for industrial applications.