Multi-material braids for multifunctional laminates: conductive through-thickness reinforcement

• Main Authors: Caroline O’Keeffe, Laura Rhian Pickard, Juan Cao, Giuliano Allegri, Ivana K. Partridge, Dmitry S. Ivanov
• Format: Article
• Language: English
• Published: SpringerOpen 2021-02-01
• Series: Functional Composite Materials
• Subjects: Tufting; Micro-braiding; Functional composites; Electrical conductivity
• Online Access: https://doi.org/10.1186/s42252-021-00018-0

Abstract Conventional carbon fibre laminates are known to be moderately electrically conductive in-plane, but have a poor through-thickness conductivity. This poses a problem for functionality aspects that are of increasing importance to industry, such as sensing, current collection, inductive/resistive heating, electromagnetic interference (EMI) shielding, etc. This restriction is of course more pronounced for non-conductive composite reinforcements such as glass, organic or natural fibres. Among various solutions to boost through-thickness electrical conductivity, tufting with hybrid micro-braided metal-carbon fibre yarns is one of the most promising. As a well-characterised method of through thickness reinforcement, tufting is easily implementable in a manufacturing environment. The hybridisation of materials in the braid promotes the resilience and integrity of yarns, while integrating metal wires opens up a wide range of multifunctional applications. Many configurations can be produced by varying braid patterns and the constituting yarns/wires. A predictive design tool is therefore necessary to select the right material configuration for the desired functional and structural performance. This paper suggests a fast and robust method for generating finite-element models of the braids, validates the prediction of micro-architecture and electrical conductivity, and demonstrates successful manufacturing of composites enhanced with braided tufts.