Civil Engineering Reference
In-Depth Information
Results:
According (
2.77
) the rope torque is
M = 0.102
16
40,000 - 0.212
16
2
40,000
0.002094 -0.376
10
-3
16
4
0.002094
76,000
M = 65,800 - 4,540 - 3,920
M = 56,800 N mm = 56.8 Nm.
2.4.2.3 Definition of Non-rotating Rope
The spiral strand ropes are designated for supporting loads without turning pro-
tection. Therefore they should be rotation-resistant to a great extent. This will be
succeeded only approximately. Really non-rotating spiral strand ropes do not exist.
But it is useful to define the limit up to this a wire rope can be declared as a non-
rotating one.
A proposal for the definition of a non-rotating wire rope is:
A wire rope counts as non-rotating if the twist angle rests smaller than
360
1
;
000
d
u
L
during the tensile loading between
S
d
2
¼ 0 o
S
d
2
¼ 150
N/mm
2
:
2.4.2.4 Spiral Round Strand Ropes
From 48 spiral round strand ropes with three strand layers (with between 14 and 20
outer strands) seven ropes are not non-rotating for the given definition. On the
other hand from the 25 tested spiral round strand ropes with two strand layers (with
between 10 and 12 outer strands) six ropes are still non-rotating.
The non-rotating spiral strand ropes show—if not twisted—torque-tensile-force
lines with a small buckling and a mean constant c
1
= 0.026 with the standard
deviation s = 0.012. For all these ropes the torque constant c
1
, calculated with
(
2.76
) on the base of geometrical data, has been very well confirmed by the torque
zero is to lead back on the rope geometry not optimal chosen. Under the specific
tensile force S/d
2
= 0-150 N/mm
2
the ''non-rotating ropes'' show the mean twist
u/1,000d = -40/1,000d in turning on direction with the standard deviation
s = 140/1,000d.
The low-rotating spiral round strand ropes with two strand layers show—if not
twisted—a nearly straight torque-tensile-force line with c
1
= 0.058. For a small
twisting up to 90/100d a nearly straight torque-tensile-force line is only to expect
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