| 초록 |
Acoustic emission (AE) can monitor the fracture behavior of composite materials, and can characterize many AE parameters to understand the type of microfailure sources during the fracture progressing. When tensile loading is applied to a composite, AE signal may occur from fiber fracture, matrix cracking, and debonding at fiber-matrix interface. Polymeric polyvinylidene fluoride (PVDF) sensor can be directly embedded and attached to a structure. In this work, interfacial properties and damage sensitivity for single fiber/epoxy composite were studied using PVDF and lead-zirconate-titanate (PZT) sensors. PVDF sensor was embedded or attached in the epoxy matrix, whereas AE sensor was attached on matrix surface. Interfacial shear strength (IFSS) measured by PVDF sensor was smaller than that of PZT sensor due to their low sensitivity. AE sensor detected signals of fiber fracture, matrix cracking, and interfacial debonding, whereas PVDF sensor detected fiber fracture signal only. Sensitivity of embedded PVDF sensor was the almost same compared to the attached case. Acknowledgement: This study was supported financially by KOSEF through the Research Center for Aircraft Parts Technology (ReCAPT), GNU. |
