Damage Analysis of Polymer Matrix Composites by Acoustic Emission Testing

Abstract

This article shall illustrate which general information about damage accumulation, critical damage stages and macro-crack propagation in polymer matrix composites arise from conventional AE features and analysis of AE signals. It is referred to currently used methods for classification and identification of AE sources. Results of the theoretical analysis of inter-fiber and fiber fracture in laminates under tension are compared with monitored stress dependent AE behavior. Fracture mechanics investigation of the mode I, mode II and mixed-mode I/II delamination behavior of unidirectional, continuous fiber-reinforced laminates accompanied by AE examinations are discussed. AE results from pressure tests of damaged filament wound all-composite pressure cylinders are presented and criteria for identification of “heavy ” damages are suggested. Finally, particular problems with the identification of AE source mechanisms in polymer matrix composites are pointed out.