BA_TASC_PUH_6541.docx
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5.1 TRACTOR WITH MULTI-AXLE TRAILER (D VALUE):
The
D value
is defined as the theoretical representative force for the horizontal component of the
force between vehicle and trailer in longitudinal axis of the vehicle. The D value is calculated from
the two admissible total weights (tractor and multi-axle trailer) as follows:
R
T
R
T
g
D
+
=
in kN
T: admissible total mass of the vehicle in tons
R: admissible towed mass in tons
g: acceleration due to gravity = 9.81 m/s
2
The D value calculated for the tractor/trailer combination may be less than or equal to the D value
of the coupling.
Sample calculation:
T = 8,5 t; R = 31,5 t
D = 9,81 ×
8,5⋅31,5
8,5+31,5
= 65,7 ⋅ kN
5.2 TRACTOR WITH CENTRE-AXLE TRAILER (Dc VALUE, VERTICAL LOAD S RESP. S VALUE):
The
Dc value
is calculated in accordance with 5.1. Instead of the total mass R of the trailer, the total
mass C of the rigid drawbar trailer must be taken into account.
In this case, attention must additionally be paid to the admissible static vertical load at the coupling
point.
The
static vertical load S
is defined as the load transmitted by the centre-axle trailer at the coupling
point in static state.
The maximum admissible vertical load depends on the data of the connected devices (the lower
value applies in each case).
