BMW F11 Service Training page 26

F11￿Body.
2.￿Body.
5￿Series￿Touring,￿development￿of￿body￿lightweight￿construction￿and￿static￿torsional￿rigidity
Index
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The￿static￿torsional￿rigidity￿is￿the￿tendency￿of￿the￿body￿to￿twist￿around￿an￿axis￿when￿a￿force￿(torque)￿is
applied.￿Since￿a￿conflict￿of￿objectives￿exists￿between￿lightweight￿construction￿and￿rigidity,￿it￿is￿always
necessary￿to￿consider￿the￿lightweight￿construction￿quality￿in￿addition￿to￿the￿static￿torsional￿rigidity.
The￿lightweight￿construction￿quality￿describes￿the￿static￿torsional￿rigidity￿value￿in￿relation￿to￿the
surface￿area￿on￿which￿the￿car￿stands￿(track￿x￿wheelbase)￿and￿the￿weight￿of￿the￿body￿shell￿(without
doors,￿hood￿or￿rear￿hatch).￿This￿value￿describes￿the￿rigidity￿achieved￿with￿how￿little￿mass￿in￿relation￿to
the￿surface￿area￿on￿which￿the￿car￿stands.
On￿the￿F11.￿intelligent￿geometric￿design￿of￿the￿load￿paths￿in￿combination￿with￿lightweight￿materials
resulted￿in￿a￿lightweight￿construction￿factor￿of￿2.7.
2.7.￿Accident￿research
2.7.1.￿Preventative￿measures
Due￿to￿the￿extreme￿loads￿encountered￿in￿racing,￿the￿following￿measures￿were￿taken￿for￿maximum
driver￿safety￿in￿addition￿to￿the￿design￿of￿the￿passenger￿safety￿cell:
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Explanation
Static￿torsional￿rigidity
Lightweight￿construction
E39/2￿Model￿year￿1997
E61￿Model￿year￿2004
F11￿Model￿year￿2010