A study of the effect of microcrack on the vibration mode shape

摘要

This paper presents the modal analysis of an aluminum 6061 sheet in te presence of microcracks. Microcracks were introduced at the center of the sheet by compression loading and monitoring the deformation using the Acoustic Emission Technique (AET). Modal analysis was conducted on the sheet under free boundary condition. The mode shapes were mapped using the vibration pattern imager (VIP) when the sheet was vibrated at the modal frequency. The overall shape did not provide any information regarding the elastic consgtraints introduced due to the presence of microcracks. Scans were made at distances of 5 mm intervals on either side of the plastically deformed region on the plate in the horizontla and the vertical directions.