Page 550 - Automotive Engineering Powertrain Chassis System and Vehicle Body

Standard sedan (saloon) – baseline load paths C HAPTER 16.2

Plan Rear view
h
L I pr
I pt h pf

F ypr /2
R ZYR
21
18
F ypf /2 F ypr /2
(xi)
R /2 F ypf /2 R ZYF
YF
t f t r
R /2 F
F ypt
y
YR
F y R ZYF
17 20 F ypt
F ypf /2 F ypr /2 R ZYR
/2
R YF
R YR /2 /2
I 3 F ypr /2 F ypf
I 1 I 4 I 2 h pt
h l
Fig. 16.2-24 Baseline model – lateral loading.
Returning to Fig. 16.2-24 and the plan view, take
moments about the front suspension:

R YR ¼fF ypf ðl 1 þ l 3 Þþ F ypr ðl 1 þ l Þþ F ðL þ l Þ
4
l
yl
F ypt l pt g=L
Resolving lateral forces:
R YF ¼fF ypt þ F ypf þ F ypr þ F g R YR
yl

16.2.4.2 Additional SSSs for lateral load case
As the lateral forces act through the centres of mass of
the power-train and the luggage and are in front of and
behind the centre floor additional SSSs (17) to (22) are
required to those shown in Fig. 16.2-1 and are shown in
Fig. 16.2-23. SSS (19) will transfer the power-train force
as vertical forces in the planes of the front inner wing
panels and it will be assumed the lateral force is shared Fig. 16.2-25 Baseline model cross-beams – lateral loading.
equally between SSS (17) and SSS (18) (see Fig. 16.2-24).
Similar conditions are assumed to act at the luggage floor
beam. As the beams (19) and (22) cannot take moments 16.2.4.2.2 Transverse floor beam (front) (1)
about the vehicle z-axis, the beams (17), (18), (20) and By taking moments about one end
(21) act as simple cantilevers protruding forward and
0
rearward from the central floor. P ¼ F ypf pf (16.2.30)
h =w
1
Consider the cross-beams all shown in Fig. 16.2-25.
Resolving forces laterally
16.2.4.2.1 Engine beam (19)
P 0 ¼ F (16.2.31)
By taking moments about one end 16 ypf
P 0 ¼ F ypt h pt =t (16.2.28)
14 f 16.2.4.2.3 Transverse floor beam (rear) (2)
Resolve forces laterally By taking moments about one end
0
P 0 15 ¼ F ypt =2 (16.2.29) P ¼ F ypr h pr =w (16.2.32)
2

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