The role of ply clustering in the impact damage of woven carbon/epoxy laminates: An experimental-numerical study

This study investigates the impact behaviour of carbon/epoxy woven laminates through experimental and numerical analysis, with particular emphasis on the effects of ply clustering. Drop weight tower tests were performed for three different ply clustering configurations. In addition, 3D Digital Image Correlation (DIC) techniques were used to analyse out-of-plane displacements, providing a deeper insight into the phenomenon that triggers the failure mechanisms. Internal damage was further characterized using ultrasonic C-scan techniques to quantify the extent of damage. A major contribution of this work is the development of a three-dimensional constitutive model based on continuum damage mechanics that incorporates multiple failure mechanisms, with special attention to transverse shear damage. Numerical simulations of the drop-weight tower tests were performed for all three laminate configurations, validating the ability of the constitutive model to predict force and energy responses, as well as the failure mechanisms observed during the tests. The constitutive model was found to be useful in understanding the interaction between interlaminar and intralaminar failure mechanisms under out-of-plane loading conditions, such as drop weight tower tests and other impact scenarios. The study highlights the importance of laminate clustering for perforation resistance and the need to incorporate transverse shear damage into numerical models to accurately capture the perforation process.