Engineering Design of Multilayer Graphene Coated Film and Its Application in Hybrid Ballistic Panels

Abstract

This research aims to optimise the construction of ballistic panels for body armour by hybridisation in order to improve the ballistic performance. Twaron® woven fabrics and multilayer graphene (MLG) coated films were used as components for hybrid design of the panels. Two complementary research approaches were employed in this study, the empirical method for preparation and evaluation of MLG coated film and the Finite Element (FE) analysis for hybrid armour panels. The first part of this research was focused on the systematic preparation of MLG membrane coated on polyethylene (PE) film by using the chemical vapor deposition method. The effects of the growth parameters on the synthesis of MLG membrane were explored understanding of the mechanisms. Experiments showed that the tensile strength of the MLG coated film increased 7 times and the Young’s modulus 5 times more than that of pure PE film under the ratio of methane to hydrogen of 35/100 sccm. Insufficient hydrogen failed to activate the surface-bound carbon for continuous MLG growth, and an optimal condition for achieving continuous and well-defined MLG was identified. The second part of this research concentrated on the ballistic characteristics of hybrid armour panels consisting of Twaron® fabrics and MLG coated films in different positions. The staggered FE models at yarn level in perforated case and FE models of multilayer panels at fabric level in non-perforated case were established respectively. In the non-perforation case, the energy absorption increased from front layer and reached to the maximum value in the last perforated layer and then decreased gradually in the following back layers. The hybrid panel exhibited better ballistic performance when the MLG coated films were placed behind the last perforated fabric layer. A 1.8 mm reduced backface signature (BFS) was achieved when compared to the fabric panel with similar areal density. Based on such findings, a hybrid design concept was put forwarded. The heavyweight fabrics as shear resistant layers were used in the first group to resist the shear strength generated on the striking face. The lightweight fabrics were combined in the second group due to the higher energy absorption capacity. MLG coated films were placed behind the last perforated layer in the third group to minimise BFS of the panel. The hybrid panels were designed and evaluated. In the non-perforation case, the optimised hybrid panel using three components in the most effective positions exhibited significantly lower BFS. Such hybrid design makes best use of different available materials to achieve the improvement of ballistic performance of a panel.

Date of Award	1 Aug 2022
Original language	English
Awarding Institution	The University of Manchester
Supervisor	Coskun Kocabas (Supervisor) & Xiaogang Chen (Supervisor)