Page 551 - Automotive Engineering Powertrain Chassis System and Vehicle Body

CHAP TER 1 6. 2 Standard sedan (saloon) – baseline load paths

Resolving forces laterally Resolve forces horizontally
0
P ¼ P 0 (16.2.40)
P 0 17 ¼ F ypr (16.2.33) 5 4
The right-hand front inner wing panel has similar load
16.2.4.2.4 Luggage beam (22) values but all are in the opposite sense giving similar
By taking moments about one end equations.

P 0 18 ¼ F h =t r (16.2.34) 16.2.4.2.7 Front parcel shelf (6)
yl l
This member is attached to the dash panel and the
Resolving forces laterally
windscreen frame at the front edge but with no attach-
P 0 19 ¼ F =2 (16.2.35) ment at the rear. Therefore, no lateral loads can be ap-
yl
0
plied. The forces from the inner wing panels P 4 are
0
Now moving to the front structure around the engine reacted by the forces P 7 acting on the sideframe.
compartment (Fig. 16.2-26), consider each SSS. By taking moments
0
0
P w P t ¼ 0 (16.2.41)
16.2.4.2.5 Lower rails of front inner panels 7 4 f
(17 and 18) The rear structure is shown in Fig. 16.2-27 and has
By taking moments about the rear end similar loading conditions to the front structure.
0
M 1 ¼ R YF l 1 =2 P ðl 1 þ l pt Þ (16.2.36) 16.2.4.2.8 Lower rails of rear quarter panels
15
(20 and 21)
Resolve forces laterally
Resolve forces laterally
P 0 20 ¼ R YF =2 P 0 15 (16.2.37)
P 0 21 ¼ R YR =2 P 0 19 (16.2.42)
16.2.4.2.6 Left-hand front inner wing panel (3)
By taking moments about the front end
Resolve forces vertically
0
0
M ¼ R YR l 2 =2 P ðl 2 þ l Þ (16.2.43)
l
19
2
0
P ¼ R ZYF P 0 14 (16.2.38)
3
16.2.4.2.9 Left-hand rear quarter panel (7)
By taking moments about lower rear corner
Resolve forces vertically
0
ðl
P ¼fR ZYF l 1 P 0 14 1 þ l pt Þg=h 1 (16.2.39) 0 0
4
P ¼ R ZYR P
8 18 (16.2.44)
By taking moments about lower front corner
0 0
P ¼fR ZYR l 2 P ðl 2 þl 1 Þg=h 2 (16.2.45)
9 18
Resolve forces horizontally
P 0 10 ¼ P 0 9 (16.2.46)
The right-hand rear quarter panel (8) has opposite forces
acting on it and these will produce identical equations.
16.2.4.2.10 Rear parcel shelf (10)
Similar to the front parcel tray, no lateral forces act on
this member.
By taking moments
0
0
P w P t r ¼ 0 (16.2.47)
9
12
By working through the equations (16.2.28) –
(16.2.47) in the sequence shown, all the unknowns (i.e.
0
0
0
0
0
0
0
0
0
P 1 . P 5 ,P 7 . P 10 ,P 12 ,P 14 . P 21 ,M 1 and M 2 ) can
Fig. 16.2-26 Baseline model (front structure) – lateral loading. be evaluated.
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