Page 530 - Automotive Engineering Powertrain Chassis System and Vehicle Body

Terminology and overview of vehicle structure types C HAPTER 16.1

Fig. 16.1-21 Citroe ¨ n 11 CV of 1934 (courtesy of Automobiles Citroe ¨ n SA).

compared (Fig. 16.1-22). The torsion stiffness rose from An interesting ‘hysteresis’ effect is visible in the
934 N m/deg. (689 lbft/deg.) for the chassis and body unloading curve for the separate frame vehicle, due to
(together) for the earlier model to 3390 N m/deg. slippage between body and chassis at the mounting bolts.
(2500 lbft/deg.) for the integral body. This is absent in the integral structure. Swallow also

2500

Unitary chassis body
Unloaded
2000

Loaded

1500
Torque in LBFT Steel body and

together
1000 chassis frame bolted
Loaded
Unloaded

500

0
0 30′ 1° 1°30′ 2°
Twist in deg.
Fig. 16.1-22 Torsion stiffness tests, 1938 and 1939 (Swallow 1938 by permission Council of I.Mech.E.).

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