Performance Evaluation of Piezoelectric Fiber Composite Transducers on Fiber-reinforced Composite Plates

• Main Authors: Chiu, Cheng-Wei, 邱政維
• Other Authors: Yin, Ching-Chung
• Format: Others
• Language: zh-TW
• Published: 2016
• Online Access: http://ndltd.ncl.edu.tw/handle/23046553839257175135

碩士 === 國立交通大學 === 機械工程系所 === 104 === This thesis evaluates the performance of two kinds of piezoelectric fiber composite (PFC) transducers, which are used to actuate and sense the Lamb waves and transverse horizontal waves in fiber-reinforced composite laminates. Composite specimens include single layer glass/epoxy plates, a balsa wood sandwiched between two skins of woven glass/epoxy; 4-ply glass/epoxy and graphite/epoxy specimens were also considered. A pulse Nd:YAG laser was used to generate thermo-elastic plate waves for experimental determination of the dispersion curves of plate wave propagation in composite specimens. The experimental results indicate that most energy carried by the plate wave localizes in the skin layer. The radiation patterns and mechanical response spectrum induced by both PFC transducers adhered on composite specimens were measured. The measured mechanical responses have been compared with the simulated results to assist explaining phenomena. Examination of defect detection using both PFC transducers has been carried out. Two artificial defects are considered. The first is an inclusion of release cloth in a composite laminate. The second is a coin attached on to the surface of a specimen. The signal amplitudes appear with significant differences, up to 14%. It has been shown that the PFC transducers have a capability to detect the embedded and surface defects in composite laminates.