Transverse Cracking in a Cross-ply Composite Laminate - Detection in Acoustic Emission and Source Characterization

Abstract

Transverse cracking detection in a uniaxially loaded symmetric cross-ply hybrid composite laminate is studied using modal-based acoustic emission (MAE) method. Transverse cracking in the hybrid laminate is identified in conjunction with the finite element analysis and acoustic emission (AE) testing on unidirectional carbon/epoxy specimens. Higher wave modes are involved in various damage events in both types of specimens. Wave attenuation in the hybrid laminate is observed to be much stronger than in the unidirectional carbon/epoxy specimen, resulting in fewer AE events detected. A material failure kinetics-based characterization of the transverse cracking process is proposed. Results of dynamic response analysis of the hybrid laminate show good agreement with the AE experiment data.