NONDESTRUCTIVE EVALUATION OF COMPOSITE BOGIE USING INFRARED THERMOGRAPHY TECHNIQUE

초록

As increases in the speed of train, the running safety of the railway rolling stocks has become one of important issues. Also, recent concerns on the environmental issues have made the progress on energy efficiency. In the areas of railway rolling stocks, there has been every effort to reduce the weight of overall rolling stock in terms of energy efficiency. The possible example of this trial could be the use of composite materials for the carbody or bogies in railway rolling stocks. The composites provide the characteristics of lightweight, a good corrosion resistance, and a reasonable strength as compared with metallic materials. Also, infrared (IR) thermography is a powerful NDE technique for the characterization of thermal phenomenon in engineering components and/or systems including engineering materials. The high-speed IR camera provides the measurement of temperature change during mechanical testing as well as the images of temperature contour on the surface of object. In this investigation, the lock-in thermography was employed to evaluate the defects in a composite bogie. Prior to the actual nondestructive evaluation of the bogie, in order to assess the detectability of known flaws, the calibration panel was prepared with various dimensions of artificial flaws. In summary, the defect assessment results with lock-in thermography method showed a good agreement as compared with the visual inspection results. Moreover, it was found that the novel infrared thermography technique could be an effective way for the inspection and the detection of surface defects on composite bogies since the infrared thermography method provided rapid and non-contact investigation of the composite bogies.