Lightweight garage #17 CFRP components for the VW XL1 (2013)

Published on

Lightweight garage, News
©Thomas Wolf, www.foto-tw.deVolkswagen XL1, CC BY-SA 3.0 EN

The vehicle

VW started working on the one-liter car concept back in 2002. Production of the 200 units of the XL1 began in 2014. According to the manufacturer, fuel consumption is less than 1 liter per 100 km, to which the low overall mass of the model contributes significantly.

The use of lightweight materials is crucial here: 21.3 percent of the vehicle's mass is made up of carbon fiber reinforced plastic (CFRP) parts, while a further 22.5 percent is made up of light metals. The lightweight construction solutions in the body and monocoque area are particularly interesting.

The technology

The CFRP components of the monocoque and bodywork, which are mainly manufactured using the resin transfer molding (RTM) process, enable a significant reduction in weight. The body of the XL1 weighs just 230 kg. At the same time, the low weight has no negative effect on the mechanical properties of the structure. This is due to the very good specific mechanical properties of CFRP. The use of fibre-plastic composites allows additional directional mechanical properties of the structure to be achieved, enabling extensive optimization of lightweight construction.

Rainerhaufe, Body XL1 Gläserne Manufaktur, CC BY-SA 4.0

In the RTM process, dry semi-finished fiber products are placed in a two-part mould, which is then closed. In the next step, the reaction resin is injected under pressure. After complete impregnation, the component is cured under holding pressure. In the RTM process, comparatively high fiber volume fractions of over 50% can be achieved, which has a positive effect on the mechanical properties of the finished components. The process is also easy to automate, which ensures a high level of reproducibility.

The lightweight aspect

The specific weight of the carbon fiber-reinforced outer skin of the XL1 is only 20 percent of a comparable steel outer skin. At the same time, the low weight does not have a negative effect on the mechanical properties of the structure.

This might also interest you:

You can find all TGM articles here.