A Methodological Approach to the use of Natural Fiber Reinforcements in Sporting Goods

Abstract

In the field of sports, the use of natural composites, such as flax and hemp, is practically non-existent. In addition to the well-known advantages provide by composites, these natural composites have better vibration damping than glass or carbon composites which is very important in most sporting activities. Unlike carbon fiber composites, natural fiber composites have a ductile fracture behaviour without sharp fibers which improves safety compared to carbon fiber composites. However, although the future of these materials looks promising, it seems difficult to believe that any user would be willing to sacrifice technical performance or safety for a more sustainable product. Therefore, a number of uncertainties need to be overcome before natural composites can be introduced into the design of sports equipment. Overcoming these uncertainties requires an in-depth knowledge of these material systems, in which the mechanical properties and behaviour are highly dependent on the manufacturing processes. This knowledge can be achieved through the complete characterisation of the material, especially in many aspects of its behaviour in which there is not yet adequate information to be able to design components with high structural requirements. In this study, a methodology was developed to cope with the design and development of sport components with structural and vibration absorption requirements, such as a bicycle handlebar and a paddle racket. The process begins with the selection and subsequent characterisation of sustainable material systems. For this purpose, the mechanical properties and the damping factor of the material were analysed, taking into account the orientation of the reinforcement fibers. The experimental results are used in the development, simulating by means of finite elements the structural and vibrational behaviour. Once this behaviour has been optimised, prototypes are manufactured using both composite materials with natural reinforcements, in this case flax. The prototypes are tested to validate the behaviour at component level and the necessary improvements are proposed to comply with all the requirements that must be met by each type of product. The mechanical performance and carbon footprint is compared to the conventional counterpart solution.