Designing Lighter Vehicles with Composite Components
Lightweight design in automotive development means less material, lighter vehicles, and therefore less CO2 emissions. Developments in material technology has allowed for the production and use of composites in many automotive components but until recently, these components were usually non load bearing and non safety related parts. A recent study at Volkswagen Group Research aimed to define a B-pillar from composite material and to develop a robust and efficient design approach to develop composite components with optimized performance and weight, at competitive manufacturing costs.Solution
Altair ProductDesign was selected by Volkswagen to support this project. The main objective was to define a general process for a new, robust, and efficient design approach with the ability to develop all types of composite components and above all, test and validate them by means of simulation.
The optimization of fiber composite materials calls for a three step process. During the ‘free size’ optimization, the Volkswagen and Altair engineers define where the single fiber layers of each orientation are needed, the following ‘size’ optimization defines the amount of layers needed, and the final shuffle optimization identifies the optimal stacking sequence of the composite plys. The engineers were looking for a compromise between a very light but complex component and one that can be produced easily.Result
This development phase resulted in a B-pillar showing a similar stiffness as the original B-pillar made of metal and a weight reduction of around 40%. The different fiber composites could take in up to 25% more energy at 30% less mass than the metal component. However, the results also showed a higher deformation of up to 30%, which is not acceptable for the B-pillar of a car. As an effective countermeasure, the B-pillar would have to include some enforcing ribs which would reduce some of the weight advantages of the material.
The foremost goal of the study, however, was to show that the chosen development process was practicable for load bearing structures made of fiber composites and future adjustments to the development process at Volkswagen will lead to the possibility to take advantage of the potential of fiber composites for many additional vehicle components.