Articulated vehicles form an important part of our society for the transport of
goods. Compared to rigid trucks, tractor-trailer combinations can transport huge
quantities of load without increasing the axle load. The fifth wheel (FW) acts
as a bridge between the tractor and trailer, which can be moved within the range
to achieve rated front and rear axle loads. When the FW is moved front, it
adversely affects the cab dynamics and cab suspension forces. Compared to the
cab pitch and roll, yaw motion increases drastically. The current study tries to
address this issue by providing reaction rod links in the rear cab
suspension.
In this study, a 4×2 tractor with a three-axle semitrailer is considered by
keeping the FW at its frontmost position, which is the worst-case scenario for a
cab. Three different cases of reaction rod arrangement and its influence on cab
dynamics are studied in comparison with a model without reaction rods. To assess
this, time signal–based relative pseudo-fatigue damage, power spectral density
(PSD), and level crossing plots are analyzed.
The outcome shows that cab pitch, roll, and yaw motion reduce by a considerable
amount with the presence of a reaction rod. Cab suspension forces will also
reduce. The horizontal V-inclination of the reaction rod plays a major role in
improving cab yaw motion and reducing the lateral forces. A straight link
without any inclination helps in reducing the pitch and roll motion of the
cab.
