Finite element analysis and acoustic emission monitoring of progressive failure of corrugated core composite structures

The present work investigates the progressive failure in a corrugated core type CFRP composite structure under out-of-plane compression and four-point-bending tests. The structure has a novel geometry where unidirectional prepreg is used for both the corrugated core and the facesheets, which are manufactured together in a single process. Acoustic Emission (AE) registration is applied during the four-point-bending test and the k-means++ clustering algorithm is used to group the similar AE events and provide reliable correlations with failure modes. Test results are complemented with finite elements progressive failure analysis in which Hashin's failure criterion and Cohesive Zone Model are utilized to predict the intralaminar and interlaminar damage modes respectively. The model is validated by comparing it with load-displacement curves and observed failure modes during the tests. Analysis of AE results reveals failure modes during four-point bending test and provides reliable evidence which is in good agreement with the predictions of the finite element model.