Innovation and Analysis of Police Riot Helmets with Continuous Textile Reinforcement for Improved Protection

摘要

At the present there exist two different types of riot helmet shells, a thermoplastic and a composite shell. The composite shell is believed to be superior in impact performance, but more expensive and complicated in manufacturing partially due to the fact that the textile reinforcement material has to be cut into pattern pieces before they can be applied to the helmet shaped mould. However, the discontinuation of fibers is likely to reduce the level of protection and shorten the lifetime of a helmet. The aim of this research is to develop a helmet shell consisting of a single-piece of fabric without creating wrinkles and without the necessity of cutting the fabric. For this purpose, a new type of woven fabric has been developed and an apparatus has been set up to drape the fabric to a helmet shell. The helmet shell was manufactured using a single piece of Kevlar woven fabric. In parallel the finite element method is applied to investigate the shock absorption behaviour of the helmet shell made from both multi-piece and single-piece fabric reinforcements. The results show clearly the advantage of the single-piece helmet shell over its existing multi-piece counterpart