Body - SMART Series 451 Service Manual

SN_Typ 451_us.book Seite 113 Freitag, 30. November 2007 1:56 13
Bodyshell structure
The bodyshell structure of model series 451 exhibits
the following features:
• tridion safety cell with high-strength steels and
low weight:
— smart fortwo coupé: 352 lb (160 kg)
— smart fortwo cabrio: 379 lb (172 kg)
• Light alloy detachable parts
• Front CMS
• Rear CMS
tridion safety cell
The tridion safety cell which forms the bodyshell
ensures that the vehicle is robust, absorbs energy by
deformation in the event of a crash and provides
optimum protection of the survival space to keep the
occupants safe.
Design-based benefits of tridion safety cell:
• Its longitudinal members and crossmembers
absorb impact energy at front and rear
• The most important major assemblies are safely
accommodated in its underfloor area.
• Crash boxes attached at the front and rear absorb
the impact energy at speeds of up to approx. 10
mph (16 km/h).
• It supports the extendable steering column via the
cockpit crossmember.
The tridion safety cell consists of more than 50
percent high-strength steel sheet. These steels are
alloyed to be more rigid and stronger than standard
steel sheet.
The high-strength sheet metal parts can be worked in
the same way as standard sheet metal and provide the
following benefits:
• Improved torsional stiffness
• Optimized crash behavior
• Reduced metal sheet thickness
• Weight saving
Bodyshell material diagram of the steels used (coupé
and cabrio)
Silver areas
The silver areas are soft deep-drawing steels of
regular strength. In these areas all the usual welding
methods can be used.
Red areas
The red areas consist of micro-alloyed high-strength
steels. Resistance spot welding can easily be carried
out in these areas.
However, metal active gas (MAG) welding is only
permissible on approved areas. See the Workshop
Information System (WIS) for further instructions and
information.
Green area (cabrio only)
The green area consists of a particularly high-
strength and torsionally stiff martensite phase steel.
This steel is only used in the cabrio for the window
pillars of the A-pillars because particularly stringent
demands are made on the strength of the vehicle at
these points.
Introduction of the smart fortwo, Model Series 451

Body

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