Predicting bird impact response and damage behavior of three-dimensional woven composites using a localized subcell model

It is important to study the impact response and damage behavior of composites due to the growing number of aircraft accidents caused by bird strikes. This study examines the response of three-dimensional woven composite (3DWC) plates to impacts by birds, in which quasi-static and impact tests were conducted. An efficient local homogenization modeling approach that avoids manual division was developed. The proposed model employs a specified subdomain to loop the unit cell for the automatic generation of yarn subcells and matrix subcells. The subcell model of the unit cell is then assembled into a large-size macrostructure for bird impact simulations, and the simulations were found to provide good predictions of impact response, yarn damage, and matrix damage. The impact tests and simulation results were used to analyze the deformation and damage behavior of the 3DWC plate in detail. The results show that matrix cracks and matrix spalling are the dominant damage modes and slight fiber breakage only occurs for impacts with high energy. Matrix damage primarily occurs near the rear surface of the composite plates due to tensile stress. It is also found that composite plates impacted by small birds exhibit a higher energy absorption ratio than plates struck by large birds for impacts with comparable impact energy. The findings of this study are expected to provide guidance on the anti-bird strike design of woven composites.