Mercedes-Benz B-Class

The combination of safety, sportiness and style puts the new Mercedes B-Class at the cutting edge of technology. Every detail of the new model is impressive: the highest safety standard ever in a compact car, outstanding ride comfort, low fuel consumption and a premium interior. The second generation of the B-Class heralds the start of a new era of compact cars in terms of both concepts and technology. The Bertrandt Technikum provided broad-based support for the development process.

The Bertrandt Technikum provided development services for the compact sports tourer

Development partner with comprehensive expertise

The Bertrandt site in Ehningen took responsibility for complex components as part of the process of designing and developing the new B-Class, with the main focus being on the vehicle body development department. Bertrandt’s projects involved services ranging from virtual CAD development of the body-in-white components, doors, closures and subframe through to tolerance management, conversions of pre-production vehicles, endurance testing and support for the prototype production plant. In addition, the Bertrandt engineers were responsible for producing visualisations for presentation documents and rendering the body-in-white components.

 

Innovative and flexible

One particular challenge relating to the body-in-white involved a new development method: Daimler’s CAD template process. For the first time, the vehicle body was fully networked. This means, for example, that when the outer shell is redesigned, it is not only the side panels that change, but also the components behind them. This new high-tech procedure brings many advantages for the development process, including guaranteeing greater efficiency, improved quality and better knowledge management. The CAD template process, which includes fully networked and configured data for all the body-in-white components, allows for more efficient working methods and higher quality data. This integral approach and the heavily networked development process require a larger number of interfaces and more communication, but the increased amount of preparatory work reduces costs by around 30 % for the base model and 50 % for the derivatives. The innovative template process, which the Bertrandt engineers used for the first time, was also accompanied by a detailed tolerance management process which began at an early stage and which Bertrandt took partial responsibility for.

Aufwändige 3-D Visualisierungen veranschaulichten die Eigenschaften der B-Klasse-Rohkarosse für den EuroCarBody Award.

Modular body-in-white concept

Bertrandt’s involvement in the project started very early and covered all the design and development phases. Work on developing the different derivatives was staggered. The focal point of Bertrandt’s services was the complete body-in-white. Its modular concept presented a particular challenge. The idea behind this was to design the B-Class from the beginning to accommodate an alternative drive system. Interfaces in the body allow the main floor panel to be modified for the versions with a different drive system. For example, various derivatives of the A-Class and B-Class have the same engine bulkhead, but different windscreen positions. The modular structure enables a variety of distinctive body variants to be produced which use a high proportion of the same components. The intelligent system makes a broad range of different body variations possible.

 

Prototypes and endurance testing

The tasks which Bertrandt was given responsibility for included project management and design engineering for special test vehicles. Components such as axles and powertrains are integrated into these vehicles and tested at an early stage. Bertrandt also provided support for the process of planning endurance tests for the B-Class transmissions. In addition, Bertrandt’s endurance testing team contributed to the complete vehicle tests.

 

Support for production start-up

The Bertrandt team’s services also covered the production processes and the start of manufacturing at the prototype production plant in Sindelfingen, with a focus on the technical validation of the structure of the prototype and validation vehicles. Virtual assembly tests, together with tests on the vehicles themselves, were carried out to evaluate possible solutions. Finally, Bertrandt provided support for the start of volume production at the plant in Rastatt and later in the new factory in Kecskemét in Hungary.

Winner of the EuroCarBody award

Bertrandt helped Daimler AG to produce a presentation for EuroCarBody, the global car body benchmarking conference in Bad Nauheim, where the B-Class was one of the winners of the world’s most prestigious bodywork prize, the EuroCarBody award, in the body-inwhite and production categories. The very close coordination between the partners, which was based on mutual trust, resulted in excellent cooperation throughout all the phases of the development process. The short distance between the Bertrandt and Daimler sites allowed Bertrandt to meet its customer’s requirements quickly and efficiently.

 

A new era in the compact class

Other characteristic features of the new B-Class, alongside the flexible design engineering methods, the new template process and the modular bodyin- white, include excellent results in the NCAP crash test. The compact sports tourer comes as standard with a radar-based collision warning system with adaptive Brake Assist, which reduces the risk of a rear-end collision. The B-Class is the first compact car to be fitted with the PRE-SAFE® preventive occupant protection system. The new model also has impressive aerodynamics figures, including a drag coefficient of only cd = 0.26, which makes it the best in its market segment. Bertrandt took up the challenge as a partner of Daimler AG and provided end-to-end development expertise as its contribution to a new era in the compact class.