Experimental and Finite Element Investigation in Defect Detecting of Polymer Matrix Composite Pipes by Non-Destructive Infrared Thermography Test

In this paper, the evaluation of infrared thermography has been done to detect subsurface defects of polymer composite pipes made by filament winding method. In this method, in order to stimulate the test specimen, the heat flux is applied over the surface of the specimen and the thermal response is processed to detect defects. Experimental investigation was applied by hot air, optical pulse, and modulated stimulation on specimens were made with common controlled defects in composite materials. Interpretation of the results were utilized in the calculation of defects’ size and location, it was observed that in specimen with 4 mm thickness dry fiber defect with a minimum size of 3040 mm, delamination and inclusion defects with a minimum size of 25*25 mm clearly is detected and is measured. The evaluation of thermal stimulation techniques shows in the examined samples, according to the type of cylindrical structure and ability of applying thermal fluid to its internal side, the method of hot air stimulation by the blower is a reliable method and provides trusted results.