The race is on in the composite industry to make significant progress in providing lightweight and economical series production large parts to the automotive industry. Once associated mainly with F1 track racing vehicles, composites are now prevalent in many high-end sports cars and super hybrid cars, including the BMW i8 and the Porsche 918 Spyder.
Both vehicles are gas-electric hybrids that claim significant use of composites. The BMW i8 uses carbon fiber in the passenger cell and in the body panels, which is also matched with an aluminum chassis and safety structure. The “alien-tech” Porsche 918 Spyder, as it is referred to by Car and Driver Magazine in its October Lightning Lap No. 8 issue, employs an all carbon-fiber-reinforced plastic monocoque chassis and carbon-fiber passenger cells.
In the August/September issue of JEC Composites Magazine, which is dedicated to automotive composites, editor Frédéric Reux notes that while the BMW i8 and the Porsche 918 Spyder are not mass-produced, they aren’t isolated occurrences either. Progress is being made and manufacturing advances in composites will both join and challenge lightweight metals in providing parts to the automotive industry.
Among these developments are the use of natural fibers such as flax and hemp, which have favorable stiffness and impact properties along with offering some added end-of-life benefits. 3D fabrics and billets hope to overcome the limitations (delamination being the most common problem) typically associated with 2D approaches, while also serving as a medium for incorporating various hybrid materials. The outcome of these advancements is better performance and lower costs.
Additive manufacturing, the industrial version of 3D printing, with graphite and non-metals is showing strong promise for creating difficult geometries and an array of brackets and body-panel fill-ins. The debate remains, however, on how to achieve larger or more complex parts in fewer production steps, while also meeting automotive surfacing and structural requirements. The ultimate goal is to establish fully automated process chains.
Today, the most difficult challenge remains in the post-design stages. In the early development stages much has been accomplished, because, as is the case with Dassault Systèmes, integrated programs exist to virtually create, optimize, test, validate and prepare composite models for processing, whether it be with hemp, Kevlar, graphite or something entirely new!
For more on Dassault Systèmes products for composite development, click here. For a close look at the tradeoffs made between composites and metals and to watch a hot lap of the Porsche 918 Spyder, click here.
