Benteler develops pioneering door concept without B-pillar

German metal processing specialist company Benteler has developed a new door concept that removes the need for a B-pillar. This production-ready product is even lighter than existing solutions on the market and offers improved safety and material features. It not only makes mobility lighter, safer and more sustainable but also more convenient and makes vehicle entry easier.

Due to megatrends such as electrification and automated driving, the development departments of automotive manufacturers are increasingly looking at different structures for vehicle interiors.

According to Christian Hielscher, R&D Manager Advanced Structural Systems, Benteler, "We have developed an integrated solution that meets all dynamic crash and static load requirements. In this way, we are making a significant contribution to lightweight construction."

Eco-friendly aluminium alloy
In addition to its materials competence, Benteler has contributed its expertise in metal processing. The know-how for crash-tested lightweight solutions is evident in the use of the key aluminium alloy for increased protection of occupants and the environment.

"The aluminium used makes an active contribution to environmentally friendly vehicle recycling. With the production of the structural components, for example, we ensure that the door can be recycled into equivalent products at the end of the vehicle’s life cycle. This is achieved by using a single grade of aluminum alloy," says Dr Jorn Tolle, R&D Teamleader Lightweight Technologies. As a result, the solution not only saves resource-intensive development time, but also brings decisive weight and CO2 savings.

Crash-proven concept brings decisive lightweight advantages
The aim of the concept and structural development was to integrate the B-pillar function into the door structure – while meeting all crash and static requirements. The aim was to find the lightest possible solution. This was the starting point for the virtual development of the crash structures. The Benteler engineers used the full vehicle model from the EU-funded ALIVE project. Benteler Automotive was involved in this from 2012 to 2016. The aim was to develop key technologies for lightweight vehicle construction based on advanced metal and hybrid materials for future electric vehicles.

According to Benteler, the innovative door concept based on an aluminium structure made of AlSiMg grade alloy exhibits very good properties in all load cases and meets or exceeds even the requirements from the ALIVE reference vehicle. It shows that the optimization of the body is particularly important: especially in terms of torsional stiffness and roof crush as well as the door structure with regards to side crashes. Furthermore, this result was achieved with only very little additional weight of the vehicle, which is a great success compared to the few solutions currently in series production.

Automotive manufacturers and engineering service providers thereby benefit from a pre-developed crash structure that creates more space in the vehicle interior thanks to the new structure with the B-pillar integrated in the door. In addition, it can be adapted and transferred to series production with little effort.