2015 Volume 15 Issue 3 Pages 175-180
This paper introduces “Tapping AE method” which is a new Non-destructive testing method for Carbon fiber reinforced plastic (CFRP). Although it has many advantages, internal damage easily occurs in CFRP components even by a small out-of-plane load. The typical non-destructive methods for CFRP are ultrasonic testing (UT) and tap testing. Although UT has high detectability, UT is a time and cost consuming method. On the other hand, tapping method is a quick and easy way to conduct, although, the detectability is insufficient. The aim of developing tapping AE method is realizing high-detectability tap testing. In Tapping AE method, the specimen is tapped by a hammer and secondary AE emitted from the damages are measured by AE sensor installed in the hammer during the hammer tapping. In order to evaluate feasibility of tapping AE method, we developed tapping AE system. The test was applied to a cross-ply CFRP laminate with and without internal damages. During the test, we observed secondary AE signals from the damaged specimen. New parameter, RMSratio was defined to evaluate secondary AE signals. Compared with the result of traditional tapping method using contact duration, the result of proposed method using RMSratio shows high detectability.
