Development of a program for automatic calculation of the delamination factor using image processing techniques

Abstract

The production of composite materials, such as fiberglass epoxy laminates, has increased in response to the demand for lightweight and rigid components. Drilling is a common process applied to these materials but often induces delamination damage at entry and exit points. This study presents an image processing technique developed to calculate the delamination diameter (D_max), hole diameter (D), delamination area (A_d), and hole area (A). To determine actual dimensions, photographs were captured with a ruler marked by two red lines placed over the holes. The pixel equivalent of the distance between the lines was computed, after which the ruler was removed from the image. A thresholding method was employed to binarize the image, marking pixels in the damaged area as black and other pixels as white. Additionally, the ratio of black pixels to the pixel count of the hole area was calculated. Both diameter and area ratios were utilized to determine delamination factors. Results demonstrated that both conventional and adjusted delamination factors could be computed. The developed technique enables automatic calculation of delamination factors using only a ruler and a camera, offering economic and time-saving advantages compared to alternative methods due to minimal equipment requirements and preparation.