A Systems Approach in Developing an Ultralightweight Outside Mounted Rearview Mirror Using Discontinuous Fiber Reinforced Thermoplastics

Fuel efficiency improvement in automobiles has been a topic of great interest over the past few years, especially with the introduction of the new CAFE 2025 standards. Although there are multiple ways of improving the fuel efficiency of an automobile, lightweighting is one of the most common approaches taken by many automotive manufacturers. Lightweighting is even more significant in electric vehicles as it directly affects the range of the vehicle. Amidst this context of lightweighting, the use of composite materials as alternatives to metals has been proven in the past to help achieve substantial weight reduction. The focus of using composites for weight reduction has however been typically limited to major structural components, such as BiW and closures, due to high material costs. Secondary structural components which contribute approximately 30% of the vehicle weight are usually neglected by these weight reduction studies. This work is an attempt to prove that composites can also be used effectively in the weight reduction of secondary structural components, while meeting the desired standards on mechanical performance, cost, and scalability. Discontinuous fiber-reinforced injection-molded materials offer excellent mechanical properties and very high lightweighting potential. In this paper, a secondary structural component such as outside mounted rearview mirror assembly is used to study the effect of performance and cost while trying to achieve a mass reduction of at least 30%. An injection-molded long carbon fiber-reinforced nylon is used to replace the aluminum structure in the baseline mirror assembly. In addition to material replacement, 20%-parts consolidation was achieved due to the design freedom offered by these materials. A virtual plant layout was developed to determine the cost of series manufacturing. In conclusion, this paper provides a strong case for the use of these material systems to lightweight small and secondary structural components.