Application of Electrical Stimulation for Inspection of Composite Materials in The Thermography Method

In this Paper, thermography inspection of carbon fiber reinforced composite parts made by two methods of vacuum infusion and manual layering has been investigated. In this method, composite materials are subjected to a direct electrical stimulation including voltage of 5 volts, current of 1.6 amps for 1-2 seconds and are heated uniformly. By means of an infrared camera, non-destructive evaluation of these parts is conducted. Since the first signs of defects in the electrical stimulation are changes in temperature, this method greatly contributes to the quality of the thermal images taken by the infrared camera and the accuracy of the test. By applying the electrical conductive stimulation directly to the samples, cracks with dimensions of 2 and 1.5 cm in the hand layup parts and cracks with dimensions of 2, 1.5 and 1 cm in parts made by vacuum infusion method were detected. Direct stimulation by means of electrical conductive makes the method more flexible in many real parts that cannot be tested with conventional methods like direct heating or flashlights.