Interesting info from JESMB on the safety and body materials of the new S-class.
The passive safety of the new Mercedes S-Class
The new S-Class from Mercedes offers new crash structures, a new center airbag and, for the first time, a rear frontal airbag
Intelligent body-in-white concepts and innovations in restraint systems underpin the S-Class's pioneering role in passive safety. The new aluminum hybrid bodyshell, with an aluminum content of over 50 percent, meets many requirements: high crash safety, a weight that is up to 60 kg less than that of the predecessor, and outstanding body rigidity for excellent driving characteristics with the best possible noise and vibration comfort.
The body of the new S-Class was designed with a special focus on lightweight construction. The newly developed aluminum-steel hybrid shell increases the proportion of aluminum to over 50 percent of the weight. The high proportion of aluminum is achieved through the use of cast and extruded structural components. This lightweight construction of materials and shapes results in a high level of complexity in the joining technology. It characterizes the know-how of Mercedes-Benz in the luxury sedan segment as well as the quality experience of barely noticeable, narrow body joints and the high form accuracy of the design surfaces.
The extensive package of lightweight construction measures includes the stiff extruded aluminum profiles for the side members in the front, rear and side. Specially developed, highly integrative die-cast aluminum components are used at the important structural nodes.
The highly stable side wall structure comprises the pillars, the side roof frame and the side longitudinal members. The material mix of aluminum and high-strength steels helps to resolve the conflicting goals between lightweight construction and crash design. The inner shells are partially composed of several components, with the node connections between the pillars, roof frame and side longitudinal members being designed over a large area in accordance with the load.
One-piece side wall cladding in aluminum is a very effective lightweight construction measure. Great emphasis was placed on the realization of narrow joints and radii with a high perceived value. The outer skin of the roof as well as the bonnet, fenders, trunk lid and doors are also made of sheet aluminum.
Passenger cell: Protection through ultra-high-strength and press-hardened steels
The Mercedes-Benz safety cell forms the core of the safety design. The structure consists of a supporting structure of hot-formed steel cross members of the highest strength in the areas of the front wall and rear end. This is completed on the sides by extremely stiff sills in extruded aluminum profile construction with a profile that is even larger than its predecessor and four internal chambers.
The floor structure also uses ultra-high-strength and press-hardened steels, which combine to form a highly functional platform. The stresses of all load cases are introduced into the main floor. The robust center tunnel and the side rails form the basis for this. These assemblies are connected via further cross and diagonal support components. The design of this support structure makes it possible to make the floor panels lighter. You thus make a significant contribution to weight efficiency. The tunnel load level, which is particularly necessary for a frontal impact, is achieved by interconnected profiles made of high-strength steels. The wall thicknesses vary according to the load.
Stem: partner protection for those involved in an accident
The front structure consists of an upper ring structure, the side members and the integral support. Additional plastic connecting elements between the crash levels ensure particularly favorable energy dissipation in the early crash phase. The integral support houses the engine, the steering and the lower suspension arms and, in the event of a frontal collision, transfers the longitudinal forces directly into the floor structure through a special crash support. The cross connections in the front end can activate the side facing away from the impact in the case of partially covered frontal collisions, for example the right side of the structure in the case of a partially covered left side collision and vice versa.
In the event of greater deformation, the wheels are supported on the stable side wall and the wheel impact element in front. The sill was specifically designed with regard to geometry and strength. Above the pedal base, the front wall is reinforced by an external cross member made of high-strength steel, which is supported on the A-pillars.
In addition to self-protection, compatibility with other vehicles was an important development goal. For this purpose, in addition to the previous concept, the front bending beam, for example, was designed in such a way that an even more stable and flat impact plane is created for the accident partner.
Rear car: two zones with different tasks
The safety level of the rear structure is largely achieved by dividing it into two crash zones. The zone in which the tank components are located is kept almost deformation-free by cast aluminum components. In the crumple zone behind it, energy is primarily dissipated with the help of extruded aluminum structures. In the event of partially covered accidents, the rear bending cross member also transfers the loads to the side facing away from the impact, so that both longitudinal member paths can be activated.
The new center airbag can be seen between the driver and front passenger seats - it prevents the heads from colliding
Restraint systems: innovations for the passengers in the rear
In the S-Class in particular, the focus has always been on safety in the rear. Mercedes-Benz has been expanding the airbag and belt systems there for a long time. Large windowbags cover the window sides like a curtain. Depending on the type of impact, they can be triggered as needed in the event of a severe side impact or rollover. The belts of the outside seats are fitted with belt tensioners and force limiters as standard, which help to reduce the stress levels of the occupants. Rear sidebags are optionally available as well as the beltbag: an inflatable belt strap distributes the load on the upper body over a larger area.
The rear airbag is a novelty at Mercedes-Benz: This additional airbag can further increase the level of safety for passengers in the rear seat in the event of a serious frontal collision. It is and remains important that the occupants always buckle up. This is made easier for you in the rear by the optional, illuminated designer seat belt buckles.
lower right airbag in the seat cushion of the executive seat (prevents diving under the belt in the lying position); above the new rear frontal airbag
