Modal Acoustic Emission Investigation for Progressive Failure Monitoring in Thin Composite Plates under Tensile Test

Abstract

Acoustic Emission (AE) is one of the popular non-destructive (NDT) techniques and its applications have increased subsequently for Structural Health Monitoring (SHM). During the past few decades, many successful research works have evidently shown remarkable capability of AE for early damage detection of composite materials. This paper investigated the application of single channel acoustic emission (AE) source location detection method, utilizing time-frequency analysis for thin composite plates. Besides, failure characterization using Modal Acoustic Emission (MAE) also presented. Modal analysis of AE signals or MAE can offers a better theoretical background for acoustic emission analysis; which is necessary to get more qualitative and quantitative result and therefore, increase the reliability of early failure characterization for thin composite plates. For this study, tensile tests were conducted on the glass fiber epoxy resin specimen with small notch; and four channels of acoustic emission system were used to acquire AE signals. The results revealed that in practical, single channel AE source location was difficult to be done. Also, the study has successfully showed that matrix cracks and fiber fracture produced AE signals which dominated by symmetric wave mode.