Nanotek and Expo

Biography

Biography: Joung-Man Park

Abstract

Carbon fibers are used as sensing elements in CFRP due to their electrical conductivity. In some more advanced studies, in CRFP, the carbon fibers were used for both strain sensing and damage sensing. The basic theory, in such studies, was that the movement of carbon fiber could be detected by ER (ER) measurement. This work evaluated the potential use of carbon fiber/polypropylene-polyamide (CF/PP-PA) composites in thermoplastic automobile applications. Two dimensional electrical resistance (2D ER) mapping was used to sense and predict damages. The extent of random dispersion of carbon fibers (CF) in PP-PA matrix was evaluated using 2D ER mapping contour charts. ER data collected at nine different positions was used to evaluate dispersion and micro-damages. The uniformity of dispersion of CF in fractured surfaces was observed for comparison. Pyrolyzed specimens were used to measure CF amount in each part and compared with 2D ER mapping. The differences in ER for tensile and compressive stresses were compared to explore their usage for real time monitoring and sensing of damages. The observation of the fractured surfaces exhibited an acceptable consistency with 2D ER results. Ultimately 2D ER mapping should be useful for evaluating and predicting damages in CF/PP-PA composites under various loading conditions. This may have some very significant practical importance. It may point the way to use quick easy tests to screen and predict other mechanical failure behaviors for composites of different materials and/or processes. Perhaps a simple 2D ER mapping test might be used to predict and select good candidate materials, surface processing techniques for various high strength composite applications.