Soft body armour is usually constructed by layering numerous layers of the same fabric. Such a construction, however, may not be the most efficient in providing the required protection due to different ballistic resistant efficiency of each layer. This research aims to optimise the construction of the panels for soft body armour by hybridisation in order to achieve the improvement of ballistic performance and reductions in weight. Twaron woven fabrics with different weave structures and Dyneema uni-directional (UD) laminates were used as components for the hybrid design of panels. Two complementary research approaches were employed in this study, namely the empirical method and the Finite Element (FE) analysis. The first part of this research systematically revealed the different ballistic characteristics of each layer in different positions of an armour panel and the way of energy absorption in the panel. The fabric layers in the front, middle and back of the panel exhibited different extent of transverse deformation and stress distribution. The energy absorption increases from front layer and reaches to the maximum value in the last perforated layer and then decreases gradually in the following back layers. Such pattern of energy absorption was not affected by either the striking velocity or the total number of layers in the panel, but the position, in the thickness, of the peak value in energy absorption was shifted more towards the back of the panel when the striking velocity increases. Such findings contribute to the understanding of different ballistic responses in different positions of an armour panel under ballistic impact. The second part of this research put forward a new hybrid design concept. According to above theoretical understandings of different ballistic characteristics in different positions of an armour panel, the fabric layers in the panel were discretely divided into three groups. In addition to the performance of different components for the panel and the influences of the laying sequence, a procedure for constructing hybrid armour panels has been established. The first group was composed of the first few layers on the striking face. The heavyweight fabrics as heat resistant layers were used in this group to resist the heat generated on the striking face. The second group contained some middle layers close to the last perforated layers. The lightweight fabric was combined in this group due to the higher energy absorption capacity. All back layers were classified into the third group. Dyneema UD laminates were placed in this group to constrain the large transverse deflection of the lightweight fabric and to minimize BFS of the panel. Two hybrid panels were designed and evaluated. In the perforation ballistic tests, the hybrid panel was more likely to stop the projectile compared to Twaron woven panels with the same areal density. In the non-perforation ballistic tests, the hybrid panel exhibited significantly lower BFS and achieved the reductions in weight. Such hybrid design makes best use of different available materials to achieve the improvement of ballistic performance and lightweight of a panel. It has a practical significance for the soft armour panel design.
Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:728115 |
Date | January 2016 |
Creators | Yang, Yanfei |
Contributors | Chen, Xiaogang |
Publisher | University of Manchester |
Source Sets | Ethos UK |
Detected Language | English |
Type | Electronic Thesis or Dissertation |
Source | https://www.research.manchester.ac.uk/portal/en/theses/study-on-ballistic-performance-of-hybrid-soft-body-armour(005e442a-a334-4b6d-83c2-e46014856a44).html |
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