Delamination Modes in Composite Plates

Abstract

In this paper, modal analysis experiments on composite plates with and without delaminations are carried out. Specimens of the glass cloth and epoxy matrix composite plate, including plates without delamination and plates with through-width delaminations, are manufactured by the layup technique. A thin Teflon film is used to introduce the delamination during the manufacturing process. Delamination modes are found in delaminated plates by comparing the modal analysis results of the delaminated plates with the results of the nondelaminated plates. The sensitivity of the Teflon in the delamination area to the delamination modes is analyzed by the modal analysis experiments of the plates with Teflon in and out of the delamination area. Two delamination coefficients are defined to discern the delamination modes more quantitatively. According to the modal analysis results, the possibility of detecting the delamination size and location is discussed.