Crashworthiness Improvements to Automotive Sandwich Composites Using Tufting

Abstract

With the growing demand for battery electric vehicles (BEVs), a focus within the automotive industry is ensuring vehicle performance can meet customer demands. Electric powertrains are inevitably much heavier than existing internal combustion systems, which severely limits the range of the vehicle. To compensate for this, automotive manufacturers are now looking to exploit fibre-reinforced composites (FRPs) to reduce the structural weight of the vehicle.

One route to achieving this is using lightweight composite sandwich structures, which show great potential because of their good mechanical performance and low density, as well good damping properties. However, relatively poor interfacial properties render these structures unreliable when it comes to the demanding safety requirements that must be in place to protect the vehicle occupants during a crash. Through-thickness tufting has recently been demonstrated to be a promising method for reinforcing dry sandwich preforms, showing improvements in the crash performance whilst offering improvements in processability over more conventional through-thickness reinforcement methods. However, while promising results have been demonstrated there is still much to be understood of the failure behaviour of these structures, as well as the influence that design and manufacturing variables can have on this.

This work aims to develop a deeper understanding in this field, to help influence and improve the future design of these structures. This is achieved using several novel experimental techniques designed to capture the behaviour of these structures at a level of detail not seen before. Testing has looked at the failure mechanics of tufted sandwich structures, as well as the influence of the tuft structure and material selection from an automotive-focused viewpoint. The output of this work proposes desired design choices and failure behaviour for high energy absorption, as well as possible design improvements for increased structural efficiency, and offering suggestions for the future direction of research.

Date of Award	24 Mar 2020
Original language	English
Awarding Institution	The University of Bristol
Supervisor	Carwyn Ward (Supervisor) & Ivana K Partridge (Supervisor)